In this research, we used mean shift clustering (Comaniciu & Meer, 1999) to detect cross points. Mean shift is a well-known algorithm for finding the local maximum of an underlying density function. Here, a Gaussian kernel is used, where *σs* and *σt* stand for the kernel size in the space and time domains, respectively. We implement the mean-shift algorithm with *σs* = 0.15 m *σt* = 0.5 sec. The detected cross points are indicated by solid circles in Fig. 8. It can be seen that the cross points have been correctly detected. More details of this process can be found in our previous research (Shao et al., 2006).

**5. Experiment**

observation fields.

camera.

**5.2 People tracking in crowd**

**5.1 Experimental conditions**

We evaluated the effectiveness of the proposed method through an experiment conducted at a railway station in Tokyo, which is used by roughly 250,000 people per day. The station concourse is about 20 meters by 30 meters, and can hold over 150 passengers at a time.

Human Sensing in Crowd Using Laser Scanners 27

Figure 9 shows a plane view of the concourse and the locations of the sensors. The shadow areas are indicated in the observation field. The darker the shadow, the greater the number of sensors observing the area. Eight laser sensors (#1 through #8) were set up around the most crowded area. Furthermore, in order to evaluate the proposed method with real-world conditions, the authors set up several cameras to obtain video. Six cameras (#C3 - #C8) were positioned on the ceiling to take video from directly above the concourse, and two video

Fig. 9. Sensor alignments in a railway station, where #1 to #8 and #C1 to #C8 represent the position of laser scanners, and video cameras respectively. Shadow area shows the

Figure 10 shows the results of people tracking in crowds during rush hour. The red ellipses are recognized people, and yellow points are laser points1. Although significant occlusions occur, our proposed method can robustly track each pedestrian in the crowd. We found that a maximum of 150 people could be tracked at the same time and that tracking precision

1 Calibration between cameras and lasers was done using Tsai's method (Tsai, 1987). Recognized people are approximated by a 170-cm height by 50-cm width, and back-projected to the image plane of the #C2

cameras (#C1 - #C2) were positioned to take video diagonally.

Fig. 7. Gait features

Fig. 8. Periodic spiral patterns of laser points in spatial-temporal domain. Detected cross points (CPs) representing axes of the feet are also marked by solid circles.

With the cross point *CPn k* = (*cxn k* , *cyn k* , *ctn k* ) for pedestrian *k* at measurement time *n*, step length *sn k* and cycle time *ωn k* can be computed by the following equations.

$$s\_k^n = \left\{ (c\mathbf{x}\_k^n - c\mathbf{x}\_k^{n-1})^2 + (cy\_k^n - cy\_k^{n-1})^2 \right\}^{\frac{1}{2}} \tag{12}$$

$$
\omega\_k^n = \mathfrak{c}t\_k^n - \mathfrak{c}t\_k^{n-1} \tag{13}
$$

Moreover, walking speed can be calculated by *vn k* = *sn k* /*ωn k* . In this research, several cross points satisfying *vn k* ≤ 0.2 m/s were eliminated, because a stationary human does not provide a spiral pattern in the spatial-temporal spaces, which leads to a detection error.

#### **5. Experiment**

12 Will-be-set-by-IN-TECH

NGPIVJ

NGPIVJ

NGPIVJ 5VGR-

5VGR-

Fig. 7. Gait features

5VGR-

**x**

*k* = (*cxn*

*s n k* =

Moreover, walking speed can be calculated by *vn*

**y**

**t**

With the cross point *CPn*

*k* and cycle time *ωn*

points satisfying *vn*

*sn*

YKFVJ

5VTKFG-

standing foot

swinging foot

*CPk n*

*k* )2 + (*cyn*

*k* − *ctn*−1

*k* = *sn*

*k* ≤ 0.2 m/s were eliminated, because a stationary human does not provide

*k* − *cyn*−1

*k* /*ωn*

Fig. 8. Periodic spiral patterns of laser points in spatial-temporal domain. Detected cross

*k* can be computed by the following equations.

*k* − *cxn*−1

*ωn k* = *ctn*

a spiral pattern in the spatial-temporal spaces, which leads to a detection error.

points (CPs) representing axes of the feet are also marked by solid circles.

*k* , *cyn k* , *ctn*

(*cxn*

*CPk n-1*

*CPk n-2*

*CPk n-3*

*CPk n-4*

*CPk n-5*

*k* ) for pedestrian *k* at measurement time *n*, step length

2 (12)

*k* (13)

*k* . In this research, several cross

*k* )2 1

#### **5.1 Experimental conditions**

We evaluated the effectiveness of the proposed method through an experiment conducted at a railway station in Tokyo, which is used by roughly 250,000 people per day. The station concourse is about 20 meters by 30 meters, and can hold over 150 passengers at a time.

Figure 9 shows a plane view of the concourse and the locations of the sensors. The shadow areas are indicated in the observation field. The darker the shadow, the greater the number of sensors observing the area. Eight laser sensors (#1 through #8) were set up around the most crowded area. Furthermore, in order to evaluate the proposed method with real-world conditions, the authors set up several cameras to obtain video. Six cameras (#C3 - #C8) were positioned on the ceiling to take video from directly above the concourse, and two video cameras (#C1 - #C2) were positioned to take video diagonally.

Fig. 9. Sensor alignments in a railway station, where #1 to #8 and #C1 to #C8 represent the position of laser scanners, and video cameras respectively. Shadow area shows the observation fields.

#### **5.2 People tracking in crowd**

Figure 10 shows the results of people tracking in crowds during rush hour. The red ellipses are recognized people, and yellow points are laser points1. Although significant occlusions occur, our proposed method can robustly track each pedestrian in the crowd. We found that a maximum of 150 people could be tracked at the same time and that tracking precision

1 Calibration between cameras and lasers was done using Tsai's method (Tsai, 1987). Recognized people are approximated by a 170-cm height by 50-cm width, and back-projected to the image plane of the #C2 camera.

cycle times, but they are separable because of their different step lengths. Pedestrian #5 was running. He walked very fast and then began to run. From Table 2 we can see that his cycle time is short and stable, with a mean of 0.33 s and a variance of 20 ms, but his step length varies greatly, from about 0.6 m to 1.5 m, because of the change from fast walking to running. In this experiment, step length and cycle time of each step were extracted from our walking model and employed with speed to analyze different walking patterns. The results demonstrate that different walking patterns have their own distributions in the step length to cycle time space, and useful information about their behavior can be obtained. More information on activity

Human Sensing in Crowd Using Laser Scanners 29

recognition using gait features can be found in the reference (Nakamura et al., 2007).

䎳䏈䏇䎃䎆䎔 䎳䏈䏇䎃䎆䎕 䎳䏈䏇䎃䎆䎖 䎳䏈䏇䎃䎆䎗 䎳䏈䏇䎃䎆䎘

䎓䎑䎕

䎓䎑䎗

䎓䎑䎙

䎓䎑䎛

䎓䎑䎗 䎓䎑䎙 䎓䎑䎛 䎔 䎔䎑䎕 䎔䎑䎗 䎔䎑䎙

Ped # Step length (m) Cycle times (s) Speed (m/s) 0.46 ± 0.02 0.54 ± 0.06 0.87 ± 0.08 0.60 ± 0.06 0.50 ± 0.07 1.21 ± 0.08 0.70 ± 0.04 0.59 ± 0.06 1.21 ± 0.08 0.87 ± 0.03 0.47 ± 0.04 1.88 ± 0.17 1.11 ± 0.29 0.33 ± 0.02 3.34 ± 0.92

Our method can be applied to analyze both crowd flow and local activities. Figure 12 shows the results of visualizing crowd flow for one day. Blue lines indicate movement from right to left, and yellow lines are the opposite flow. The red points represent static people (e.g. moving at a speed < 0.3 m/sec), and white points show collision avoidance between two people (e.g.

Fig. 11. Examples of detected gait features in different walking styles

Table 2. Statistical features of different walking styles

**5.4 Application to crowd-flow analysis**

exceeded 80% during rush hour. The average pedestrian density at this time was roughly about 0.6 people/*m*2.

The proposed method was more effective for tracking people in crowds in wide open areas than with vision-based methods. Because this method is also useful for protecting privacy due to using only range data, it can be used for sensing in areas where it is difficult to set up video cameras.

(a) frame 41 (b) frame 70

(c) frame 97 (d) frame 127

#### **5.3 Gait analysis**

Figure 11 plots the distribution of step length and cycle time of some different walking patterns. The mean and variance of step length, cycle time, and speed are listed in Table 2. The x-axis in Fig. 11 is the step length, and the y-axis is the cycle time. As we can see, pedestrians #2 and #3 have almost the same speed (average speed = 1.21 m/s and speed variance = 0.08 m/s) but they are well separated because they have different step lengths and cycle times. Also, pedestrian #4 walks stably, with a variance of step length of 3 cm and variance of cycle time of 40 ms. As another example, pedestrians #1, #2, and #3 have almost the same 14 Will-be-set-by-IN-TECH

exceeded 80% during rush hour. The average pedestrian density at this time was roughly

The proposed method was more effective for tracking people in crowds in wide open areas than with vision-based methods. Because this method is also useful for protecting privacy due to using only range data, it can be used for sensing in areas where it is difficult to set up

(a) frame 41 (b) frame 70

(c) frame 97 (d) frame 127

Figure 11 plots the distribution of step length and cycle time of some different walking patterns. The mean and variance of step length, cycle time, and speed are listed in Table 2. The x-axis in Fig. 11 is the step length, and the y-axis is the cycle time. As we can see, pedestrians #2 and #3 have almost the same speed (average speed = 1.21 m/s and speed variance = 0.08 m/s) but they are well separated because they have different step lengths and cycle times. Also, pedestrian #4 walks stably, with a variance of step length of 3 cm and variance of cycle time of 40 ms. As another example, pedestrians #1, #2, and #3 have almost the same

Fig. 10. Results of people-tracking in crowd during rush-hour

about 0.6 people/*m*2.

video cameras.

**5.3 Gait analysis**

cycle times, but they are separable because of their different step lengths. Pedestrian #5 was running. He walked very fast and then began to run. From Table 2 we can see that his cycle time is short and stable, with a mean of 0.33 s and a variance of 20 ms, but his step length varies greatly, from about 0.6 m to 1.5 m, because of the change from fast walking to running. In this experiment, step length and cycle time of each step were extracted from our walking model and employed with speed to analyze different walking patterns. The results demonstrate that different walking patterns have their own distributions in the step length to cycle time space, and useful information about their behavior can be obtained. More information on activity recognition using gait features can be found in the reference (Nakamura et al., 2007).

Fig. 11. Examples of detected gait features in different walking styles

#### **5.4 Application to crowd-flow analysis**

Our method can be applied to analyze both crowd flow and local activities. Figure 12 shows the results of visualizing crowd flow for one day. Blue lines indicate movement from right to left, and yellow lines are the opposite flow. The red points represent static people (e.g. moving at a speed < 0.3 m/sec), and white points show collision avoidance between two people (e.g.

**6. Conclusion**

a wider range of applications.

the experiment at the railway station.

*Image Understanding* 73(3): 428–440.

*Pattern Recognition (CVPR)*, pp. 423–430.

*Pattern Analysis & Applications* 2(1): 22–30.

*Pattern Recognition (CVPR)*, pp. 142–151.

*(ECCV)*, Vol. 3952, Springer, pp. 428–441.

*Machine Intelligence* 32(9): 1–20.

*and Image Understanding* 73(1): 82–98.

**7. Acknowledgment**

**8. References**

In this chapter, we described a method of human sensing in a crowd using multiple laser scanners. We evaluated the effectiveness of the proposed method for human tracking and gait analysis in a crowd through an experiment conducted at a large railway station. Our proposed method is well-suited to protect privacy because it does not use images but uses range data only. Therefore, our method is especially suitable for crowd sensing in public spaces such as railway stations, airports, and museums. We believe that this laser-based method is a necessary approach to complement vision-based methods that makes it possible to achieve

Human Sensing in Crowd Using Laser Scanners 31

We would like to thank Dr. Sakamoto and Ms. Nakagawa for their invaluable assistance in

Aggarwal, J. K. & Cai, Q. (1999). Human Motion Analysis: A Review, *Computer Vision and*

BenAbdelkader, C., Cutler, R. & Davis, L. (2002). Stride and cadence as a biometric in

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People Behavior and Indoor Temperature Distribution using Laser Range Scanners

two passengers get close to each other within 60 cm). Figure 13 shows a detected average number of train passengers during a day. We can see two peaks during the commuter rushes.

Fig. 12. Visualization results of crowd flow in one day. Blue lines are movement from right to left, and yellow lines are from left to right. Red points represent static people, and white points indicate collision avoidance between two people.

Fig. 13. Detected average number of passengers at a railway station in one day.

#### **6. Conclusion**

16 Will-be-set-by-IN-TECH

two passengers get close to each other within 60 cm). Figure 13 shows a detected average number of train passengers during a day. We can see two peaks during the commuter rushes.

Fig. 12. Visualization results of crowd flow in one day. Blue lines are movement from right to left, and yellow lines are from left to right. Red points represent static people, and white

06:00 08:00 10:00 12:00 14:00 16:00 18:00 20:00 22:00 00:00

Fig. 13. Detected average number of passengers at a railway station in one day.

Time

points indicate collision avoidance between two people.

10

20

30

40

50

Average number of passengers

60

70

80

90

100

In this chapter, we described a method of human sensing in a crowd using multiple laser scanners. We evaluated the effectiveness of the proposed method for human tracking and gait analysis in a crowd through an experiment conducted at a large railway station. Our proposed method is well-suited to protect privacy because it does not use images but uses range data only. Therefore, our method is especially suitable for crowd sensing in public spaces such as railway stations, airports, and museums. We believe that this laser-based method is a necessary approach to complement vision-based methods that makes it possible to achieve a wider range of applications.

#### **7. Acknowledgment**

We would like to thank Dr. Sakamoto and Ms. Nakagawa for their invaluable assistance in the experiment at the railway station.

#### **8. References**

**3**

*2State Aircraft Factory*

*1,2Greece*

**A Multi-Faceted Assessment of the**

 **Applications of Full Body Scanners at Airports**

Performed research indicates that the number of passengers travelling by air is increasing. Likewise, the percentage of global air cargo is growing. For safeguarding established safety levels, the International Civil Aviation Organization, ICAO, in conjunction with national Civil Aviation Authorities has introduced over the years a number of rules and frameworks that aviation companies and airports need to adhere to. Indeed, it can be argued that although ICAO's main scope is to regulate international air travel, the means and methods implied to achieve safety levels in the aviation sector remains at the corresponding Civil

An escalating number of violations of security measures over the years have led some airport authorities to impose stricter aviation-specific security techniques, suggesting that current legal, and/or technology-related frameworks ought to be further optimised. In doing so, the quest for establishing higher quality and safety levels in the aviation sector has resulted in the development, marketing and operation of Whole Body Imaging, WBI technologies. Although regarded by airport authorities as a means of either supplementing already existing security checks, or even to replace metal, or/and explosive detectors, initial research indicates that public reaction is split, as it considers issues such as religious beliefs,

The preliminary study carried out so far indicates–primarily-the application of two different strategies per se. FAA requires the use of Full Body Scanners, FBS, at American airports. Within the European Union however, the use of FBS is not yet regulated, as it awaits the

This work will acknowledge the current operating legal framework and will elaborate on contemporary implied practices, which will address the areas of quality/benchmarking, safety and security and will consider the time value of money taking into account the acquisition of such scanning machines. A potential sector-wide operation of Full Body Scanners, FBS may

Based on real-life case-studies, this research will address basic operating principles of FBS and will suggest best benchmarking practices within an applied Quality Management

equally have an effect on associated flight operations and slot management.

Aviation Authorities and the associated airport management.

**1. Introduction**

health-related and ethical issues.

environment.

outcomes of an impact assessment review.

Angelos Lakrintis1, Konstantinos Malandrakis1 and Leo D. Kounis1,2 *1Halkis Polytechnic, School of Applied Sciences, Dept. of Aviation Technology*

and Sensor Networks for Advanced Air Conditioning Control, *Proceedings of the International Conference on Networked Sensing Systems (INSS)*, pp. BOF–11.

## **A Multi-Faceted Assessment of the Applications of Full Body Scanners at Airports**

Angelos Lakrintis1, Konstantinos Malandrakis1 and Leo D. Kounis1,2 *1Halkis Polytechnic, School of Applied Sciences, Dept. of Aviation Technology 2State Aircraft Factory 1,2Greece*

#### **1. Introduction**

18 Will-be-set-by-IN-TECH

32 Laser Scanner Technology

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*Pattern Analysis and Machine Intelligence* 27(2): 162–177.

*Imformation (SSII)*, pp. 177–180.

*Recognition (CVPR)*, pp. 739–746.

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1207.

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extremely crowded scenes, *Proceedings of the IEEE International Conference on Computer*

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Filter : Multitarget Detection and Tracking, *Proceedings of the European Conference on*

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crowded environments., *IEEE Transactions on Pattern Analysis and Machine Intelligence*

Performed research indicates that the number of passengers travelling by air is increasing. Likewise, the percentage of global air cargo is growing. For safeguarding established safety levels, the International Civil Aviation Organization, ICAO, in conjunction with national Civil Aviation Authorities has introduced over the years a number of rules and frameworks that aviation companies and airports need to adhere to. Indeed, it can be argued that although ICAO's main scope is to regulate international air travel, the means and methods implied to achieve safety levels in the aviation sector remains at the corresponding Civil Aviation Authorities and the associated airport management.

An escalating number of violations of security measures over the years have led some airport authorities to impose stricter aviation-specific security techniques, suggesting that current legal, and/or technology-related frameworks ought to be further optimised. In doing so, the quest for establishing higher quality and safety levels in the aviation sector has resulted in the development, marketing and operation of Whole Body Imaging, WBI technologies. Although regarded by airport authorities as a means of either supplementing already existing security checks, or even to replace metal, or/and explosive detectors, initial research indicates that public reaction is split, as it considers issues such as religious beliefs, health-related and ethical issues.

The preliminary study carried out so far indicates–primarily-the application of two different strategies per se. FAA requires the use of Full Body Scanners, FBS, at American airports. Within the European Union however, the use of FBS is not yet regulated, as it awaits the outcomes of an impact assessment review.

This work will acknowledge the current operating legal framework and will elaborate on contemporary implied practices, which will address the areas of quality/benchmarking, safety and security and will consider the time value of money taking into account the acquisition of such scanning machines. A potential sector-wide operation of Full Body Scanners, FBS may equally have an effect on associated flight operations and slot management.

Based on real-life case-studies, this research will address basic operating principles of FBS and will suggest best benchmarking practices within an applied Quality Management environment.

A Multi-Faceted Assessment of the Applications of Full Body Scanners at Airports 35

passenger and the air carrier. Their mutual acceptance of this contract detailing potential claims and law suits in the event that either party may have failed to provide the service as stated in the Warsaw Convention of 1929 [2]. It is worth mentioning at this point that the latter was subject to two revisions, namely the Hague amendment of 1955 and that of

Research performed by Topouris *et al*, (2011), has shown that global air travel exhibits a continuous growth in passenger numbers and cargo. This in turn, necessitated -amongst others-the introduction and development of safety procedures and built-in safety devices,

The Ontario Privacy Commissioner IPC, in collaboration with the Dutch Data Protection Authority established in 1995 the term Privacy Enhancing Technologies, PETs. This refers to "…coherent systems of information and communication technologies that strengthen the protection of privacy information systems by preventing the unnecessary or unlawful collection, use and disclosure of personal data, or by offering tools to enhance an

The events of September 11th, 2001, led the Research, Engineering and Development Advisory Committee of the Federal Aviation Administration, FAA (2002), to introduce a number of approaches in order to minimise potential security threats. Among the suggestions launched, the Advisory Subcommittee proposed the adaptation of the following

Screening technology as proposed by the Advisory Subcommittee translates to Whole Body Imaging, WBI, technology. This refers to basically two different types of apparatuses, namely:

The FBS listed above, use an array of algorithms so as to provide the security controller with a detailed view of any illegal items carried by the traveler, while aiming at safeguarding

In the long-term, it is stated that the FAA would need to tackle the aviation security issue as a generic system and develop henceforth a number of technologies and techniques, capable of integrating potential threat information. It is the authors' view that this scenario would require continuous investigation. The latter ought to consider cutting-edge technology, processes and procedures alike, so as to cater for potential unauthorized "system-entries". Indeed, it can be argued that potential "loopholes" within the aviations' generic system are

The Transportation Security Administration, TSA, commenced the deployment of WBI technologies and procedures at airports. Opponents of the latter argue that it violates

Montreal in 1999.

such as metal detectors.

short-term means:

personal data.

subject to misconduct.

fundamental human rights.

individual's control over his/her data."[4].

In view of the above, the aim of this study will be to suggest alternative means of checking methods, whilst maintaining set quality levels and enhancing benchmarking tools.

In doing so, this work will address the following objectives:

#### **1.1 Initial hypotheses pertaining to safety levels in relation to quality**

Initial research carried-out indicates that a wide-spread application of Full Body Scanners, FBS falls short. This may be attributable to the following reasons:

It is the authors' view that both potential causes mentioned above should be viewed taking into consideration the "time value of money"-principle into account. This is defined as the amount of interest earned on an initial investment within a set time period. However, this term deduces a lean investment and a seamless payback period, not necessarily considering long-term "what-if" scenarios. The latter may include long-term radiation level exposure and its effects on travelers, in particular frequent flyers.

This study will emphasise the need for a multi-faceted assessment of the application of FBS at airports and major transportation hubs-such as international railway terminusconsidering potential drawbacks on the long-term. In addition to this, it will suggest alternative scanning methods that will be able to effectively detect dangerous objects, whilst minimising the radiation dosage emitted. It is worth mentioning at this point that the latter forms part of current on-going research.

#### **2. Literature review and methodology**

Safety and security are amongst the most widely coined clauses in any airline's Mission Statement. Safety is defined as "…*freedom from danger, risk, or injury"*, whereas security is described as *"…freedom from risk, or danger; safety; anything that gives or assures safety; one who undertakes to fulfill the obligation of another; surety"* [1]. The latter of the term forms part of an airline ticket and is seen as a legal term of a contract agreed and signed between the passenger and the air carrier. Their mutual acceptance of this contract detailing potential claims and law suits in the event that either party may have failed to provide the service as stated in the Warsaw Convention of 1929 [2]. It is worth mentioning at this point that the latter was subject to two revisions, namely the Hague amendment of 1955 and that of Montreal in 1999.

Research performed by Topouris *et al*, (2011), has shown that global air travel exhibits a continuous growth in passenger numbers and cargo. This in turn, necessitated -amongst others-the introduction and development of safety procedures and built-in safety devices, such as metal detectors.

The Ontario Privacy Commissioner IPC, in collaboration with the Dutch Data Protection Authority established in 1995 the term Privacy Enhancing Technologies, PETs. This refers to "…coherent systems of information and communication technologies that strengthen the protection of privacy information systems by preventing the unnecessary or unlawful collection, use and disclosure of personal data, or by offering tools to enhance an individual's control over his/her data."[4].

The events of September 11th, 2001, led the Research, Engineering and Development Advisory Committee of the Federal Aviation Administration, FAA (2002), to introduce a number of approaches in order to minimise potential security threats. Among the suggestions launched, the Advisory Subcommittee proposed the adaptation of the following short-term means:

Screening technology as proposed by the Advisory Subcommittee translates to Whole Body Imaging, WBI, technology. This refers to basically two different types of apparatuses, namely:

34 Laser Scanner Technology

In view of the above, the aim of this study will be to suggest alternative means of checking

Initial research carried-out indicates that a wide-spread application of Full Body Scanners,

It is the authors' view that both potential causes mentioned above should be viewed taking into consideration the "time value of money"-principle into account. This is defined as the amount of interest earned on an initial investment within a set time period. However, this term deduces a lean investment and a seamless payback period, not necessarily considering long-term "what-if" scenarios. The latter may include long-term radiation level exposure

This study will emphasise the need for a multi-faceted assessment of the application of FBS at airports and major transportation hubs-such as international railway terminusconsidering potential drawbacks on the long-term. In addition to this, it will suggest alternative scanning methods that will be able to effectively detect dangerous objects, whilst minimising the radiation dosage emitted. It is worth mentioning at this point that the latter

Safety and security are amongst the most widely coined clauses in any airline's Mission Statement. Safety is defined as "…*freedom from danger, risk, or injury"*, whereas security is described as *"…freedom from risk, or danger; safety; anything that gives or assures safety; one who undertakes to fulfill the obligation of another; surety"* [1]. The latter of the term forms part of an airline ticket and is seen as a legal term of a contract agreed and signed between the

methods, whilst maintaining set quality levels and enhancing benchmarking tools.

In doing so, this work will address the following objectives:

FBS already in use

specific percentages - to appraise benchmarking tools

airports that apply traditional means of checking points

FBS falls short. This may be attributable to the following reasons:

**1.1 Initial hypotheses pertaining to safety levels in relation to quality**

subjecting the scanned person to the least amount of radiation

and its effects on travelers, in particular frequent flyers.

forms part of current on-going research.

**2. Literature review and methodology**

The FBS listed above, use an array of algorithms so as to provide the security controller with a detailed view of any illegal items carried by the traveler, while aiming at safeguarding personal data.

In the long-term, it is stated that the FAA would need to tackle the aviation security issue as a generic system and develop henceforth a number of technologies and techniques, capable of integrating potential threat information. It is the authors' view that this scenario would require continuous investigation. The latter ought to consider cutting-edge technology, processes and procedures alike, so as to cater for potential unauthorized "system-entries". Indeed, it can be argued that potential "loopholes" within the aviations' generic system are subject to misconduct.

The Transportation Security Administration, TSA, commenced the deployment of WBI technologies and procedures at airports. Opponents of the latter argue that it violates fundamental human rights.

A Multi-Faceted Assessment of the Applications of Full Body Scanners at Airports 37

EU Commission Regulation 185/2010 acknowledges that: "… methods, including technologies, for detection of liquid explosives will develop over time. In line with technological developments and operation experiences both at Community and global level, the Commission will make proposals, whenever appropriate, to revise the technological and operation provisions on the screening of liquids, aerosols and gels". This is in par with the European Directive 95/46/EC concerning "…the protection of individuals with regard to the processing of personal data and on the free movement of such data". However, the Directive 95/46/EC coins the term of "necessary measure", allowing airport security to

Owing to the multiple of applicable Laws, Regulations and the novelty of the area, this work is aimed at providing all potential users of WBI technologies with a fundamental platform, taking into consideration legal/ethical, technological, quality and health-related issues.

Initial research includes the study of a number of International, European and National Laws and Regulations, which revealed that the deployment of WBI technologies and apparatuses is distinctly split between opponents and proponents. The opponents primarily

However, it is noteworthy to mention that within the EU, Member-States have decided to address aviation security by different means. As such, the United Kingdom has decided to implement FBS at all UK airports by the end of 2010, whereas in Germany, only Fühlsbüttel Airport in Hamburg is deploying such a scanner, albeit on a voluntary basis. Performed research has shown that backscatter x-ray scanners are illegal for use at German airports,

In order to provide a detailed view concerning public perception of a potential EU-wide deployment of FBS questionnaires were developed. These were targeted at random to travelling passengers from a number of Greek airports. The outcome thereof will be

When searching for the corresponding legal framework, in particular the one dealing with "Health and Safety at Work", it was found that this subject area was not addressed. In view of the above, on-going research will focus on developing alternative WBI means,

As already mentioned in chapter 2, the Obscene Publications Act 1959, OPA, of the United Kingdom sets the platform for safeguarding unlawful distribution of personal data. To this extend, it equally includes sections of the Broadcasting Act 1990 concerning the terms "programme" and "programme service". As such, the OPA introduces the so-called "test of obscenity" whereby *"…the effect of any one of its items is, if taken as a whole, such as to tend to deprave and corrupt persons who are likely, having regard to all relevant circumstances, to read, see*

In this Act "article" means any description of article containing or embodying matter to be read or looked at or both, any sound record, and any film or other record of a picture or

emphasising on effectiveness and efficiency, while minimising the emitted radiation.

represent the EU, whereas the latter stand for the United States of America.

with current research focusing on millimeter-wave scanners.

discussed as of chapter 3 on.

*or hear the matter contained or embodied in it.*

**3. Results**

pictures.

perform a detailed check, if the person is a suspect.

However, the Securing Aircraft From Explosives Responsibly: Advanced Imaging Recognition Act, S.A.F.E.R A.I.R Act, actually imposes the positioning of WBI apparatuses at airports by 2013.

Performed research reveals that the number of FBS at airports is increasing. The United States are pioneering in this area, followed by the United Kingdom, Holland and Germany to name but a few. Bart (2011), states that "…system-wide there are more than 750 screening checkpoints and over 2.000 screening lanes across 450 airports in the USA, with TSA's goal being the installation of 1.800 units by the end of 2014."

It is worth mentioning at this point that the legal framework addressing the deployment of FBS has not been finalised yet.

The European Directive No 2320/2002 sets the platform for passengers and cabin baggage screening placing the emphasis on metal detectors. However, the European Resolution (2008) 0521 of October 23rd, 2008 states that:

"…essential information is still lacking and asks the Commission, before the expiry of the three-month deadline, to:

2. Believes that this draft measure could exceed the implementing powers provided for in the basic instrument, as the measures in question cannot be considered mere technical measures relating to aviation security, but have a serious impact on the fundamental rights of citizens;…"

Preliminary research reveals that WBI technology may have long-term effects primarily on the health of passengers going through these devices. This is a focal point that is acknowledged by the EC. The latter awaits the outcome of current on-going research. The data gathered will serve as a platform in order to establish an EU-wide legal framework addressing effective and efficient security measures at airports. It is the authors' view that the long-term effects of the widespread use of FBS ought to be further researched.

Another noteworthy point is the potential infringement of fundamental human rights, considering the fact that aforementioned Resolution calls for "strong and adequate safeguards" to "protect the right to personal dignity". Finally, the Resolution stresses the fact that the impact of a wide-area deployment of FBS devices ought to protect and cater for an unlawful processing of personal data. Indeed, the latter part of the sentence is addressed by the Obscene Publications Act 1959 of the United Kingdom. To accommodate for any unlawful processing of personal data, the Obscene Publications Act introduces the term "test of obscenity".

It is the authors' view-based on preliminary research performed- that advise was not sought for at the European Data Protection Supervisor (EDPS), as required by Article 28(2) of Regulation (EC) No 45/2001. In addition to this further research ought to be carried-out, so as to include feedback from a variety of agencies such as the Fundamental Rights Agency, FRA.

EU Commission Regulation 185/2010 acknowledges that: "… methods, including technologies, for detection of liquid explosives will develop over time. In line with technological developments and operation experiences both at Community and global level, the Commission will make proposals, whenever appropriate, to revise the technological and operation provisions on the screening of liquids, aerosols and gels". This is in par with the European Directive 95/46/EC concerning "…the protection of individuals with regard to the processing of personal data and on the free movement of such data". However, the Directive 95/46/EC coins the term of "necessary measure", allowing airport security to perform a detailed check, if the person is a suspect.

Owing to the multiple of applicable Laws, Regulations and the novelty of the area, this work is aimed at providing all potential users of WBI technologies with a fundamental platform, taking into consideration legal/ethical, technological, quality and health-related issues.

Initial research includes the study of a number of International, European and National Laws and Regulations, which revealed that the deployment of WBI technologies and apparatuses is distinctly split between opponents and proponents. The opponents primarily represent the EU, whereas the latter stand for the United States of America.

However, it is noteworthy to mention that within the EU, Member-States have decided to address aviation security by different means. As such, the United Kingdom has decided to implement FBS at all UK airports by the end of 2010, whereas in Germany, only Fühlsbüttel Airport in Hamburg is deploying such a scanner, albeit on a voluntary basis. Performed research has shown that backscatter x-ray scanners are illegal for use at German airports, with current research focusing on millimeter-wave scanners.

In order to provide a detailed view concerning public perception of a potential EU-wide deployment of FBS questionnaires were developed. These were targeted at random to travelling passengers from a number of Greek airports. The outcome thereof will be discussed as of chapter 3 on.

When searching for the corresponding legal framework, in particular the one dealing with "Health and Safety at Work", it was found that this subject area was not addressed. In view of the above, on-going research will focus on developing alternative WBI means, emphasising on effectiveness and efficiency, while minimising the emitted radiation.

#### **3. Results**

36 Laser Scanner Technology

However, the Securing Aircraft From Explosives Responsibly: Advanced Imaging Recognition Act, S.A.F.E.R A.I.R Act, actually imposes the positioning of WBI apparatuses at

Performed research reveals that the number of FBS at airports is increasing. The United States are pioneering in this area, followed by the United Kingdom, Holland and Germany to name but a few. Bart (2011), states that "…system-wide there are more than 750 screening checkpoints and over 2.000 screening lanes across 450 airports in the USA, with TSA's goal

It is worth mentioning at this point that the legal framework addressing the deployment of

The European Directive No 2320/2002 sets the platform for passengers and cabin baggage screening placing the emphasis on metal detectors. However, the European Resolution

"…essential information is still lacking and asks the Commission, before the expiry of the

2. Believes that this draft measure could exceed the implementing powers provided for in the basic instrument, as the measures in question cannot be considered mere technical measures relating to aviation security, but have a serious impact on the fundamental rights

Preliminary research reveals that WBI technology may have long-term effects primarily on the health of passengers going through these devices. This is a focal point that is acknowledged by the EC. The latter awaits the outcome of current on-going research. The data gathered will serve as a platform in order to establish an EU-wide legal framework addressing effective and efficient security measures at airports. It is the authors' view that

Another noteworthy point is the potential infringement of fundamental human rights, considering the fact that aforementioned Resolution calls for "strong and adequate safeguards" to "protect the right to personal dignity". Finally, the Resolution stresses the fact that the impact of a wide-area deployment of FBS devices ought to protect and cater for an unlawful processing of personal data. Indeed, the latter part of the sentence is addressed by the Obscene Publications Act 1959 of the United Kingdom. To accommodate for any unlawful processing of personal data, the Obscene Publications Act introduces the term

It is the authors' view-based on preliminary research performed- that advise was not sought for at the European Data Protection Supervisor (EDPS), as required by Article 28(2) of Regulation (EC) No 45/2001. In addition to this further research ought to be carried-out, so as to include feedback from a variety of agencies such as the Fundamental Rights Agency, FRA.

the long-term effects of the widespread use of FBS ought to be further researched.

being the installation of 1.800 units by the end of 2014."

airports by 2013.

FBS has not been finalised yet.

three-month deadline, to:

technologies;

of citizens;…"

"test of obscenity".

(2008) 0521 of October 23rd, 2008 states that:

As already mentioned in chapter 2, the Obscene Publications Act 1959, OPA, of the United Kingdom sets the platform for safeguarding unlawful distribution of personal data. To this extend, it equally includes sections of the Broadcasting Act 1990 concerning the terms "programme" and "programme service". As such, the OPA introduces the so-called "test of obscenity" whereby *"…the effect of any one of its items is, if taken as a whole, such as to tend to deprave and corrupt persons who are likely, having regard to all relevant circumstances, to read, see or hear the matter contained or embodied in it.*

In this Act "article" means any description of article containing or embodying matter to be read or looked at or both, any sound record, and any film or other record of a picture or pictures.

A Multi-Faceted Assessment of the Applications of Full Body Scanners at Airports 39

Backscatter X-ray devices use a narrow, low-energy x-ray beam that scans the surface under

It thereafter generates a picture of the object that is projected onto a remote monitor for

Supposing that the entire dose used in order to calculate the effective dose (E) is the skin, and the "manufacturer's worst case" estimate of E = 0.0001 mSv per scan, then the worst case

It is worth mentioning at this point that performed research showed the legal ban of all backscatter x-ray devices in the Federal Republic of Germany. Further studies aim at optimising millimeter x-ray scanners, as the apparatus at Hamburg's Fühlsbüttel Airport was put out of operation. The latter was due to experienced bottlenecks, both in terms of overall passenger handling delay, as well as the number of complaints received by

Preliminary analysis shows that the radiation dosage of the backscatter x-ray scanners is:

study at a certain speed. Their operating principle is depicted in figure 2.

Fig. 2. Operating principle of a Backscatter X-Ray device

H= E / wT = (0.0001 / 0.01) mSv per scan = 0.01 mSv per scan.

equivalent dose (H) to the skin is as calculated above 0.01 mSv per scan. Table 1 shows various radiation levels from a number of human activities.

further analysis.

travelers.

For the purposes of this Act a person publishes an article who—(a) distributes, circulates, sells, lets on hire, gives, or lends it, or who offers it for sale or for letting on hire; or(b)in the case of an article containing or embodying matter to be looked at or a record, shows, plays or projects it [or, where the matter is data stored electronically, transmits that data.]

For the purposes of this Act a person also publishes an article to the extent that any matter recorded on it is included by him in a programme included in a programme service.

Where the inclusion of any matter in a programme so included would, if that matter were recorded matter, constitute the publication of an obscene article for the purposes of this Act by virtue of subsection (4) above, this Act shall have effect in relation to the inclusion of that matter in that programme as if it were recorded matter."

It is the authors' view that this Act should serve as the legal cornerstone regarding the lawful and legal handling of personal data, in association with the use of FBS. The latter is the outcome of further research by leading industries aimed at enhancing security checks at airports. As already mentioned in chapter 2, there are two different WBI apparatuses currently in use:

Millimeter wave utilises non-ionising radio frequency energy in the corresponding mmwave spectrum, so as to produce a 3D-picture of the object under study. Figure 1 shows the operating principle of such a device.

Fig. 1. Operating principle of a Millimeter wave device

The image is displayed on a remote monitor, subject to further analysis.

For the purposes of this Act a person publishes an article who—(a) distributes, circulates, sells, lets on hire, gives, or lends it, or who offers it for sale or for letting on hire; or(b)in the case of an article containing or embodying matter to be looked at or a record, shows, plays

For the purposes of this Act a person also publishes an article to the extent that any matter

Where the inclusion of any matter in a programme so included would, if that matter were recorded matter, constitute the publication of an obscene article for the purposes of this Act by virtue of subsection (4) above, this Act shall have effect in relation to the inclusion of that

It is the authors' view that this Act should serve as the legal cornerstone regarding the lawful and legal handling of personal data, in association with the use of FBS. The latter is the outcome of further research by leading industries aimed at enhancing security checks at airports. As already mentioned in chapter 2, there are two different WBI apparatuses

Millimeter wave utilises non-ionising radio frequency energy in the corresponding mmwave spectrum, so as to produce a 3D-picture of the object under study. Figure 1 shows the

or projects it [or, where the matter is data stored electronically, transmits that data.]

recorded on it is included by him in a programme included in a programme service.

matter in that programme as if it were recorded matter."

Fig. 1. Operating principle of a Millimeter wave device

The image is displayed on a remote monitor, subject to further analysis.

currently in use:

operating principle of such a device.

Backscatter X-ray devices use a narrow, low-energy x-ray beam that scans the surface under study at a certain speed. Their operating principle is depicted in figure 2.

Fig. 2. Operating principle of a Backscatter X-Ray device

It thereafter generates a picture of the object that is projected onto a remote monitor for further analysis.

Preliminary analysis shows that the radiation dosage of the backscatter x-ray scanners is:

H= E / wT = (0.0001 / 0.01) mSv per scan = 0.01 mSv per scan.

Supposing that the entire dose used in order to calculate the effective dose (E) is the skin, and the "manufacturer's worst case" estimate of E = 0.0001 mSv per scan, then the worst case equivalent dose (H) to the skin is as calculated above 0.01 mSv per scan.

Table 1 shows various radiation levels from a number of human activities.

It is worth mentioning at this point that performed research showed the legal ban of all backscatter x-ray devices in the Federal Republic of Germany. Further studies aim at optimising millimeter x-ray scanners, as the apparatus at Hamburg's Fühlsbüttel Airport was put out of operation. The latter was due to experienced bottlenecks, both in terms of overall passenger handling delay, as well as the number of complaints received by travelers.

A Multi-Faceted Assessment of the Applications of Full Body Scanners at Airports 41

When passengers were confronted with the question, if they felt secure when travelling by air, 72% responded that they did. Only a 22% was feeling insecure. The latter may be subject to further research. Likewise, airports were regarded as inducing a feeling of security to 74% of passengers, as opposed to 4% who felt not secure. By comparing these two pie-charts one

may observe that the positive responses do not show any significant variation.

Fig. 4. Customer outcome regarding airport-related security

Fig. 3. Passenger replies concerning air travel

Table 1. Radiation levels from a number of human activities

Indeed, a study by the German Radiation Protection Registry revealed some statistical data based on a study concerning the flight hours of pilots and crew members during the 5-year period 2004-2009 [14]. Authors Frasch G., Kammerer L., *et al* (2011) found that the average effective dosage of 2.35mSv per flight crew in the year 2009 was 20% higher as opposed to 2004. They justified this as being the result of "the cosmic radiation due to the altitude". Indeed, epidemiological studies point to increased health risks of flight personnel. However, an explicit correlation between altitude radiation and carcinosis is subject to further scientific research. It is therefore suggested that flight crew adhere to safety standards and optimise flight and route planning, so as to avoid high radiation areas.

In order to gauge public concern and evaluate the reactions concerning a potential use of FBS on European Airports and Transportation hubs, a questionnaire was developed and the opinion of a random sample of 50 travellers asked. The questions raised dealt with airport security matters. In particular, the query focused on how a potential introduction of FBS may affect their lives. The outcomes are shown in the following pie-charts below:

Fig. 3. Passenger replies concerning air travel

Examples mSv

Eating one banana 0.0001 mSv / banana

Sleeping next to a human for 8 hours 0.0005 mSv / night

Dental x-rays 0.005 mSv / visit

Backscatter X-ray 0.01 mSv/scan

Mammogram 3 mSv / visit

Living in San Diego (radiation from the

Living in San Diego (radiation from the

Standing in the middle of the Fukushima

Chest CT scan 6-18 mSv / scan

sky) 0.24 mSv / year

ground) 0.28 mSv / year

From your own body 0.40 mSv / year

Smoking a pack and a half a day 13-60 mSv / year

Start of level known to cause cancer 100 mSv / year

Daiichi nuclear power plant 100 to 400 mSv

optimise flight and route planning, so as to avoid high radiation areas.

Table 1. Radiation levels from a number of human activities

Airplane trip 0.01 mSv / 1000 miles flown

Indeed, a study by the German Radiation Protection Registry revealed some statistical data based on a study concerning the flight hours of pilots and crew members during the 5-year period 2004-2009 [14]. Authors Frasch G., Kammerer L., *et al* (2011) found that the average effective dosage of 2.35mSv per flight crew in the year 2009 was 20% higher as opposed to 2004. They justified this as being the result of "the cosmic radiation due to the altitude". Indeed, epidemiological studies point to increased health risks of flight personnel. However, an explicit correlation between altitude radiation and carcinosis is subject to further scientific research. It is therefore suggested that flight crew adhere to safety standards and

In order to gauge public concern and evaluate the reactions concerning a potential use of FBS on European Airports and Transportation hubs, a questionnaire was developed and the opinion of a random sample of 50 travellers asked. The questions raised dealt with airport security matters. In particular, the query focused on how a potential introduction of FBS

may affect their lives. The outcomes are shown in the following pie-charts below:

Living near a nuclear power plant 0.0001-0.01 mSv / year

When passengers were confronted with the question, if they felt secure when travelling by air, 72% responded that they did. Only a 22% was feeling insecure. The latter may be subject to further research. Likewise, airports were regarded as inducing a feeling of security to 74% of passengers, as opposed to 4% who felt not secure. By comparing these two pie-charts one may observe that the positive responses do not show any significant variation.

Fig. 4. Customer outcome regarding airport-related security

A Multi-Faceted Assessment of the Applications of Full Body Scanners at Airports 43

When further narrowing the question pertaining to the type of security device used, the responses show an approximate equal split. 40% of travellers would accept WBI technology, while 38% would not accept FBS. The remaining 22% of people quoting "not sure" needs further investigation as to the potential causes of their reply, past experience, social, moral and ethical beliefs to name but a few. The results thus far hand-shake with the initial

airports, so as to enhance an overall security feeling

Fig. 7. Potential operational impact of FBS on slots

The pie-chart shown above suggests the following:

FBS at countries already deploying them

hypotheses and indicate that:

specific security

Fig. 5. Traveler results pertaining to security measures

68% of passengers travelling by air would accept new increased security measures. The outcome of the latter contradicts previous results, which underlie the fact that on average 73% of travelers feel both secure at the airport and on the aircraft.

Fig. 6. Proponents vs. opponents of scan technology at airports

68% of passengers travelling by air would accept new increased security measures. The outcome of the latter contradicts previous results, which underlie the fact that on average

Fig. 5. Traveler results pertaining to security measures

73% of travelers feel both secure at the airport and on the aircraft.

Fig. 6. Proponents vs. opponents of scan technology at airports

When further narrowing the question pertaining to the type of security device used, the responses show an approximate equal split. 40% of travellers would accept WBI technology, while 38% would not accept FBS. The remaining 22% of people quoting "not sure" needs further investigation as to the potential causes of their reply, past experience, social, moral and ethical beliefs to name but a few. The results thus far hand-shake with the initial hypotheses and indicate that:

Fig. 7. Potential operational impact of FBS on slots

The pie-chart shown above suggests the following:

A Multi-Faceted Assessment of the Applications of Full Body Scanners at Airports 45

The outcomes received thus far indicate that further research ought to be carried-out, as the application of WBI technologies affects a multitude of transport-related areas and entities. In addition to the technology implied, the results suggest a refinement of the corresponding

With regards to increasing security measures at transportation hubs (airports and railway terminus), the "CRS Report for Congress" of May 26th, 2005, acknowledges an "*…inherently vulnerable"* state of passenger rail systems world-wide; the latter resulting from the Madrid

For an organisation to develop a thread-based risk management, Roper (1999),

Vulnerability + Threat + Criticality = Risk As such, "vulnerability" is defined as a system's open, unprotected and exposed boundaries

Likewise, "threat" refers to the potential likelihood of an attack on a system, whereas "criticality" associates the potential consequences of an attack to the system's behaviour and

The outcomes of this preliminary study and basic Extreme Value Statistics, EVS concepts suggest that the introduction of more effective security means is indeed condoned by travellers. However, public perception is split when it comes to FBS, as they are deemed to either infringe, yet even violate basic human privacy rights, or to inadvertently cause health-

The latter would have to form an area of on-going further research. It is the authors' view that no explicit scientific outcomes may be formulated, as the following factors ought to be

It primarily highlights two different areas:

legal framework, so as to:

2004 rail events.

performance.

**5. Discussion**

related diseases.

taken into consideration:

as opposed to the ones not accepting it

conceptualises it by means of the following equation:

and/or areas to potential attacks.

technology, representing 22% of the sample, and

Based on the findings of the questionnaire, passengers do indeed opt for air travel as it is a fast, safe and effective transportation means. In their view, air travel has become cheaper. Modern airplanes manage to cover long distances by offering an improved level of comfort.

Diagram 1. Trend-analysis based on the sample of 50 passengers

#### **4. Analysis**

Initial research shows that airport authorities aim at satisfying passenger needs between (95- 99)% of all times. In order for a statistical process to be regarded as being within set tolerances, the term Capability Index is introduced. Bergman and Klefsjö (1994) define capability as "*…the ability of a process to produce units with dimensions within the tolerance limits…"*.

Capability Indices, Cpks, are a simple and widely used quality technique tool (Kounis, 2010). They measure the dispersion of a process in relation to the range of the set tolerance interval, by including the Upper Specification Limit, USL, and the Lower Specification Limit, LSL. Capability Indices may equally be applied to evaluate a process, or design. The higher a Cpk value is, the lesser the amount of rejects. However, although a Cpk shows a small variation, it is not always centered around the target value (Kounis *et al*, 2000).

As Cpks, were not readily available by airport authorities, or required detailed evaluation, a sample size of 50 was deemed appropriate. Indeed, research performed by Kounis *et al*  (2000) have argued that a random sample of less than 50, may lead to making the resulting capability index Cpk unacceptable. However, the authors suggest than in cases such as inadequate funding, or inhabitive volumes, Extreme Value Statistics, EVS, may be regarded as an alternative method to capability indices, since it focuses on the behaviour of the tails of the distribution. Indeed, the authors argue that EVS "…are capable of describing these situations asymptotically."

Diagram 1 shows a trend analysis of the received outcomes to the question concerning the acceptance of scan technology apparatuses.

It primarily highlights two different areas:

44 Laser Scanner Technology

Based on the findings of the questionnaire, passengers do indeed opt for air travel as it is a fast, safe and effective transportation means. In their view, air travel has become cheaper. Modern airplanes manage to cover long distances by offering an improved level

Initial research shows that airport authorities aim at satisfying passenger needs between (95- 99)% of all times. In order for a statistical process to be regarded as being within set tolerances, the term Capability Index is introduced. Bergman and Klefsjö (1994) define capability as "*…the ability of a process to produce units with dimensions within the tolerance*

Capability Indices, Cpks, are a simple and widely used quality technique tool (Kounis, 2010). They measure the dispersion of a process in relation to the range of the set tolerance interval, by including the Upper Specification Limit, USL, and the Lower Specification Limit, LSL. Capability Indices may equally be applied to evaluate a process, or design. The higher a Cpk value is, the lesser the amount of rejects. However, although a Cpk shows a

As Cpks, were not readily available by airport authorities, or required detailed evaluation, a sample size of 50 was deemed appropriate. Indeed, research performed by Kounis *et al*  (2000) have argued that a random sample of less than 50, may lead to making the resulting capability index Cpk unacceptable. However, the authors suggest than in cases such as inadequate funding, or inhabitive volumes, Extreme Value Statistics, EVS, may be regarded as an alternative method to capability indices, since it focuses on the behaviour of the tails of the distribution. Indeed, the authors argue that EVS "…are capable of describing these

Diagram 1 shows a trend analysis of the received outcomes to the question concerning the

small variation, it is not always centered around the target value (Kounis *et al*, 2000).

Diagram 1. Trend-analysis based on the sample of 50 passengers

of comfort.

**4. Analysis**

*limits…"*.

situations asymptotically."

acceptance of scan technology apparatuses.

The outcomes received thus far indicate that further research ought to be carried-out, as the application of WBI technologies affects a multitude of transport-related areas and entities. In addition to the technology implied, the results suggest a refinement of the corresponding legal framework, so as to:

With regards to increasing security measures at transportation hubs (airports and railway terminus), the "CRS Report for Congress" of May 26th, 2005, acknowledges an "*…inherently vulnerable"* state of passenger rail systems world-wide; the latter resulting from the Madrid 2004 rail events.

For an organisation to develop a thread-based risk management, Roper (1999), conceptualises it by means of the following equation:

#### Vulnerability + Threat + Criticality = Risk

As such, "vulnerability" is defined as a system's open, unprotected and exposed boundaries and/or areas to potential attacks.

Likewise, "threat" refers to the potential likelihood of an attack on a system, whereas "criticality" associates the potential consequences of an attack to the system's behaviour and performance.

#### **5. Discussion**

The outcomes of this preliminary study and basic Extreme Value Statistics, EVS concepts suggest that the introduction of more effective security means is indeed condoned by travellers. However, public perception is split when it comes to FBS, as they are deemed to either infringe, yet even violate basic human privacy rights, or to inadvertently cause healthrelated diseases.

The latter would have to form an area of on-going further research. It is the authors' view that no explicit scientific outcomes may be formulated, as the following factors ought to be taken into consideration:

A Multi-Faceted Assessment of the Applications of Full Body Scanners at Airports 47

Fig. 8. Hypothetical scanning device based on saser technology

It is worth mentioning at this point that long-term effects ought to be studied and various external and interrelating parameters be taken into consideration.

On the other hand, research is currently focused on the development of so-called Sound Amplification by Stimulated Emission of Radiation, SASER, or sound laser. A saser is in effect a photon laser that produces a highly consistent beam of ultrasound. One might argue that a saser is a slightly modified version of a laser; the former forcing sound waves to travel at THz frequencies, albeit on a nano scale. The basic operating principle is the employment of phonons to produce sound waves. Rather than emitting waves and forcing them to pass through an optical cavity-as is the case with a laser- a saser-produced wave travels via a superlattice structure. The latter consists of 50 ultra-thin and alternating layers of gallium arsenide and aluminium arsenide. Once the phonons are inside said superlattice, they rebound, multiply and escape in the form of an ultra-high frequency beam.

The University of Nottingham has pioneered in this area

(http://www.rexresearch.com/kentsaser/kentsaser.htm). Kent *et al* argue that saser could find potential application in the manufacture of computers resulting in higher execution times.

Experiments also focus on understanding and assessing the behaviour of saser technology in spectral distribution. In particular, the detection of phonons in R1 luminescence is studied so as to draw practical applications [IOP Science] (http://iopscience.iop.org).

Another application of saser technology is to suppress the quantum noise that drowns out very faint signals in ordinary conductors [New Scientist]. The aim of on-going research is to try and reduce potential noise levels in electronic devices, so as to track down weak signals.

This paper acknowledges current research work and aims at developing a device capable of producing sound waves. These would retract once a surface or an object is been hit. Using a suitable interface, the projection of said object could be facilitated. Likewise, areas of high density could be shown by means of peaks on an oscilloscope. The hypothetical apparatus making use of saser technology is shown in figure 3.

It is the authors' view that the proposed device be simple and easy-to-use. In addition to the above, it ought to be capable of identifying and showing dangerous materials and/or tools, whilst protecting human health and personal data. The latter should be stored in means that would serve a dual purpose:

In order to enhance flight security suggested imaging apparatuses might be linked on a European-wide area, providing the outcomes of further research sectors are satisfying. This however, necessitates either amendments to current legislation, and/or the development of new EU-wide Laws. The latter ought therefore to be based on "best practice"-principles. Additional ethical and religious matters ought to be accounted for in a potential EU-wide legal framework.

It is worth mentioning at this point that long-term effects ought to be studied and various

On the other hand, research is currently focused on the development of so-called Sound Amplification by Stimulated Emission of Radiation, SASER, or sound laser. A saser is in effect a photon laser that produces a highly consistent beam of ultrasound. One might argue that a saser is a slightly modified version of a laser; the former forcing sound waves to travel at THz frequencies, albeit on a nano scale. The basic operating principle is the employment of phonons to produce sound waves. Rather than emitting waves and forcing them to pass through an optical cavity-as is the case with a laser- a saser-produced wave travels via a superlattice structure. The latter consists of 50 ultra-thin and alternating layers of gallium arsenide and aluminium arsenide. Once the phonons are inside said superlattice, they rebound, multiply and escape in the form of an ultra-high

(http://www.rexresearch.com/kentsaser/kentsaser.htm). Kent *et al* argue that saser could find potential application in the manufacture of computers resulting in higher execution

Experiments also focus on understanding and assessing the behaviour of saser technology in spectral distribution. In particular, the detection of phonons in R1 luminescence is studied so

Another application of saser technology is to suppress the quantum noise that drowns out very faint signals in ordinary conductors [New Scientist]. The aim of on-going research is to try and reduce potential noise levels in electronic devices, so as to track down weak

This paper acknowledges current research work and aims at developing a device capable of producing sound waves. These would retract once a surface or an object is been hit. Using a suitable interface, the projection of said object could be facilitated. Likewise, areas of high density could be shown by means of peaks on an oscilloscope. The hypothetical apparatus

It is the authors' view that the proposed device be simple and easy-to-use. In addition to the above, it ought to be capable of identifying and showing dangerous materials and/or tools, whilst protecting human health and personal data. The latter should be stored in means that

In order to enhance flight security suggested imaging apparatuses might be linked on a European-wide area, providing the outcomes of further research sectors are satisfying. This however, necessitates either amendments to current legislation, and/or the development of new EU-wide Laws. The latter ought therefore to be based on "best practice"-principles. Additional ethical and religious matters ought to be accounted for in a potential EU-wide

as to draw practical applications [IOP Science] (http://iopscience.iop.org).

external and interrelating parameters be taken into consideration.

The University of Nottingham has pioneered in this area

making use of saser technology is shown in figure 3.

would serve a dual purpose:

legal framework.

frequency beam.

times.

signals.

A Multi-Faceted Assessment of the Applications of Full Body Scanners at Airports 49

Bart E., "Changes in Airport Passenger Screening Technologies and Procedures: Frequently

Bergman B., Klefsjö B., "Quality: from Customer Needs to Customer Staisfaction", McGraw-

Cavoukian A, "Whole Body Imaging in Airport Scanners: Activate Privacy Filters to

Convention For The Unification Of Certain Rules Relating To International Carriage By Air,

Federal Aviation Administration, FAA, Research, Engineering and Development Advisory

Frasch G., Kammerer L., Karofsky R., Schlosser A., Spiesl J., Stegemann R., "Die berufliche

Kounis A.B., McAndrew I.R., O'Sullivan J.M., "Determining capability indices with small

Kounis, L. D., McAndrew I.R., O' Sullivan J., M: *Modelling of parametric relationships in jet*

L.D. Kounis: Robustness and Capability Indices in the optimisation of an Airline's fleet.

Peterman Randall D.: *Passenger Rail Security :Overview of Issues,* CRS Report for Congress,

Roper Carl, A. *Risk Management for Security Professionals,* Butterworth-Heinemann, 1999 S.A.F.E.R A.I.R Act, Transportation and public works. 111th Congress, 2009-2010

Strahlenexposition des fliegenden Personals in Deutschland 2004-2009", in *Bericht des Strahlenschutzregisters, Fachbereich Strahlenschutz und Gesundheit*, Salzgitter,

samples", in *Advances in Manufacturing Technology XIV*, 16th National Conference

*fans,* 3rdInternational Conference on Quality, Reliability and Maintenance, QRM 2000, pp.223-226, Ed: G. J. McNulty, University of Oxford, Oxford, United

Bridging contradicting outcomes, in "Enterprise Networks and Logistics for Agile Manufacturing", pp. 359-397, Ed. Lihui Wang and S.C. Lenny Koh, Springer Publ.,

Updated May 26th, 2005, Congressional Research Service, The Library of

Committee, *Report of the Subcommittee*, February 2002

August 2011, urn:nbn:de:0221-201108016029

on Manufacturing Research, 5-7 September 2000

Asked Questions", in *Congressional Research Service*, 7-5700, R41502, January 26th,

Achieve Security *and* Privacy", in *Information and Privacy Commissioner of Ontario,*

Signed At Warsaw On 12 October 1929 (revised at the Hague in 1955 and Montreal

**7. References**

2011

Hill, 1994 Broadcasting Act 1990

March 2009

European Directive 95/46/EC European Directive No 2320/2002

EU Commission Regulation 185/2010

IOP Science http://iopscience.iop.org

Kingdom, 30-31 March 2000

Obscene Publications Act 1959, United Kingdom

Regulation (EC) No 45/2001, Article 28(2)

Congress

September 2010, ISBN 978-1-84996-243-8 New Scientist Journal reference: *Physical Review B*, in press

European Resolution 0521 of October 23rd, 2008

in 1999)

Finally, real-life data from airports already using FBS as opposed to the ones not applying such practices ought to be performed, so as to eliminate bottlenecks and optimise benchmarking techniques. The latter ought to consider the reasoning of airport authorities that have rejected the use of body scanners, based on "not satisfying outcomes", as postulated by their users.

Further research ought to account for the cumulative radiation levels for travellers as well as flight crew, in relation to the frequency at which these are subjected to WBI apparatuses. The outcome thereof would be compared to the percentage that would show potential health-related problems over a long-term period.

#### **6. Conclusions and further work**

This work has considered current legislative matters pertaining to safety and security levels in the aviation sector. It identified open-ended issues that require further research, both in the legal, as well as the technological area. To this end, it introduced basic operating principles of millimetre and backscatter x-ray scanners, detailing their characteristics and associated drawbacks.

Performed research indicates that the perception is not unanimous. A number of countries are aiming at a sector-wide deployment of WBI apparatuses, whilst other states either seek to develop alternative means, and/or to improve on already existing ones. This trend is equally mirrored by the preliminary outcomes of the questionnaire from a sample of travellers.

Up-to-date investigations concerning alternative means of passenger checking are likewise introduced and discussed. As such, owing to the novelty and the scientific wideness of this particular area it is the authors' view that further research ought to be conducted in areas such as benchmarking/quality and its effects on an airport's overall performance. In addition to the above, further work ought to be focused on grouping of potentially dangerous articles based on their physical and/or chemical properties, so as to develop effective scanning apparatuses.

In view of the above and acknowledging the fact that the FBS positioned at Hamburg's Fühlsbüttel Airport was taken out of operation, this study is serving as the platform for optimising security means at transportation hubs. Potential operating bottlenecks-as experienced by airport authorities already using WBI technologies- will be appraised and evaluated. The outcomes thereof will form the building platform of benchmarking models to optimise passenger handling.

It is also worth mentioning at this point that no specific and accurate measures can be derived thereof, as the time interval concerning the application of FBS in relation to the potential risk of carcinogenesis, is small and yet-to-be defined. The latter would include a diverse field of further potential influencing parameters as already outlined in the study of the German Agency for Radiation Protection. In particular, a clear split of environmentspecific radiation as opposed to security-imposed radiation ought to be defined and boundaries established. For introducing a humanly-safe and secure apparatus, the effect of radiation on demographic groups ought to be further elaborated on. The latter forms part of further and continuous research aimed at identifying probable causes and interrelations.

#### **7. References**

48 Laser Scanner Technology

Finally, real-life data from airports already using FBS as opposed to the ones not applying such practices ought to be performed, so as to eliminate bottlenecks and optimise benchmarking techniques. The latter ought to consider the reasoning of airport authorities that have rejected the use of body scanners, based on "not satisfying outcomes", as

Further research ought to account for the cumulative radiation levels for travellers as well as flight crew, in relation to the frequency at which these are subjected to WBI apparatuses. The outcome thereof would be compared to the percentage that would show potential

This work has considered current legislative matters pertaining to safety and security levels in the aviation sector. It identified open-ended issues that require further research, both in the legal, as well as the technological area. To this end, it introduced basic operating principles of millimetre and backscatter x-ray scanners, detailing their characteristics and

Performed research indicates that the perception is not unanimous. A number of countries are aiming at a sector-wide deployment of WBI apparatuses, whilst other states either seek to develop alternative means, and/or to improve on already existing ones. This trend is equally

Up-to-date investigations concerning alternative means of passenger checking are likewise introduced and discussed. As such, owing to the novelty and the scientific wideness of this particular area it is the authors' view that further research ought to be conducted in areas such as benchmarking/quality and its effects on an airport's overall performance. In addition to the above, further work ought to be focused on grouping of potentially dangerous articles based on their physical and/or chemical properties, so as to develop

In view of the above and acknowledging the fact that the FBS positioned at Hamburg's Fühlsbüttel Airport was taken out of operation, this study is serving as the platform for optimising security means at transportation hubs. Potential operating bottlenecks-as experienced by airport authorities already using WBI technologies- will be appraised and evaluated. The outcomes thereof will form the building platform of benchmarking models

It is also worth mentioning at this point that no specific and accurate measures can be derived thereof, as the time interval concerning the application of FBS in relation to the potential risk of carcinogenesis, is small and yet-to-be defined. The latter would include a diverse field of further potential influencing parameters as already outlined in the study of the German Agency for Radiation Protection. In particular, a clear split of environmentspecific radiation as opposed to security-imposed radiation ought to be defined and boundaries established. For introducing a humanly-safe and secure apparatus, the effect of radiation on demographic groups ought to be further elaborated on. The latter forms part of further and continuous research aimed at identifying probable causes and interrelations.

mirrored by the preliminary outcomes of the questionnaire from a sample of travellers.

postulated by their users.

associated drawbacks.

effective scanning apparatuses.

to optimise passenger handling.

health-related problems over a long-term period.

**6. Conclusions and further work**

New Scientist Journal reference: *Physical Review B*, in press

Obscene Publications Act 1959, United Kingdom

Peterman Randall D.: *Passenger Rail Security :Overview of Issues,* CRS Report for Congress, Updated May 26th, 2005, Congressional Research Service, The Library of Congress

Regulation (EC) No 45/2001, Article 28(2)

**0**

**4**

*Spain*

Nieves Gallego Ripoll

*Universidad Politécnica de Valencia*

**Laser Scanner: eSafety & ITS Applications**

This chapter describes a proposal for a new type of Laser Scanner for use in traffic management. The chapter begins by outlining current traffic management systems, ongoing research areas and the perceived failures of present and some proposed implementations. Though the initial background presentation is long winded this is deemed necessary so the reader can gain a fuller insight into the new Laser Scanner technology being proposed.

The United Nations on its report "State of world population 2007" (UNFPA, 2007) declared that:*"In 2008, for the first time, more than half of the world's population will be living in urban areas. By 2030, towns and cities will be home to almost 5 billion people"*. This growth both in cities and inhabitants is directly proportional to mobility demands and requirements. In this situation, strategic traffic management is a key factor, even though it also involves different sectors such as economic (oil dependency), environmental (pollution, noise. . . ), safety (both drivers and

Traffic authorities are encouraged to coordinate traffic management and monitoring focusing on Road Safety problems. The Intelligent Transport Systems (ITS) is a solution in traffic management and user mobility thanks to the development and use of different applications and technologies (Ertico, 2008; ITS, 2008). Intelligent Transport Systems and Services include a wide variety of sectors and areas that previously did not have a direct connection between

ITS systems increase road safety by incorporating breakthrough technologies in different levels of management and control. These subsystems (traffic flow information systems, travelers' information systems, highways monitoring and management systems, incident management, pedestrian detection. . . ) rely on the traffic parameters provided by sensors measuring in real-time the situation on the road. The quality of the metrics received is a key for a correct network management and monitoring (García, 2000; Martin et al., 2003; Van Arem et al., 1993). The Utah Traffic Laboratory (UTL) on the report "Detector Technology Evaluation" carried out in November 2003 specifies that: *"The data collected must be plentiful, diverse, and accurate. These complex data requirements present a challenge to traffic detection systems"*(Martin et al., 2003). This statement demonstrates the importance of the traffic data

Traditionally, sensors have been used as mere measurement points, isolated from each other, that send the information to a central node which gathers the intelligence and information generated by the system (Sepulcres & Gozálvez, 2006). This node supports the applications,

pedestrians) and health (breathing problems, circulation. . . ).

**1. Introduction**

them.

and therefore of the sensor systems.

## **Laser Scanner: eSafety & ITS Applications**

Nieves Gallego Ripoll *Universidad Politécnica de Valencia Spain*

#### **1. Introduction**

50 Laser Scanner Technology

The Heritage Illustrated Dictionary of the English Language, International Edition, Vol. II,

Topouris S., Xenos-Kokoletsis A., Kounis L.D., "A feasibility study pertaining to the

University of Nottingham Ref: http://www.rexresearch.com/kentsaser/kentsaser.htm

accommodation of the A380 at Athens International Airport", Paper ID2288,

Houghton Mifflin Company, 1979

November 11-13, 2011 Zhengzhou, China

This chapter describes a proposal for a new type of Laser Scanner for use in traffic management. The chapter begins by outlining current traffic management systems, ongoing research areas and the perceived failures of present and some proposed implementations. Though the initial background presentation is long winded this is deemed necessary so the reader can gain a fuller insight into the new Laser Scanner technology being proposed.

The United Nations on its report "State of world population 2007" (UNFPA, 2007) declared that:*"In 2008, for the first time, more than half of the world's population will be living in urban areas. By 2030, towns and cities will be home to almost 5 billion people"*. This growth both in cities and inhabitants is directly proportional to mobility demands and requirements. In this situation, strategic traffic management is a key factor, even though it also involves different sectors such as economic (oil dependency), environmental (pollution, noise. . . ), safety (both drivers and pedestrians) and health (breathing problems, circulation. . . ).

Traffic authorities are encouraged to coordinate traffic management and monitoring focusing on Road Safety problems. The Intelligent Transport Systems (ITS) is a solution in traffic management and user mobility thanks to the development and use of different applications and technologies (Ertico, 2008; ITS, 2008). Intelligent Transport Systems and Services include a wide variety of sectors and areas that previously did not have a direct connection between them.

ITS systems increase road safety by incorporating breakthrough technologies in different levels of management and control. These subsystems (traffic flow information systems, travelers' information systems, highways monitoring and management systems, incident management, pedestrian detection. . . ) rely on the traffic parameters provided by sensors measuring in real-time the situation on the road. The quality of the metrics received is a key for a correct network management and monitoring (García, 2000; Martin et al., 2003; Van Arem et al., 1993). The Utah Traffic Laboratory (UTL) on the report "Detector Technology Evaluation" carried out in November 2003 specifies that: *"The data collected must be plentiful, diverse, and accurate. These complex data requirements present a challenge to traffic detection systems"*(Martin et al., 2003). This statement demonstrates the importance of the traffic data and therefore of the sensor systems.

Traditionally, sensors have been used as mere measurement points, isolated from each other, that send the information to a central node which gathers the intelligence and information generated by the system (Sepulcres & Gozálvez, 2006). This node supports the applications,

• May 2004 - UN General Assembly: Improving Road Safety. Acknowledged the release of

Laser Scanner: eSafety & ITS Applications 53

• May 2004 - World Health Assembly: Road Safety and Health. Requested to encourage research to support evidence-based approaches for prevention of road traffic injuries and

• October 2005 - UN General Assembly: Improving Global Road Safety. Encouraged international community to lead financial, technical and political support to improve road

• March 2008 - UN General Assembly: Improving Global Road Safety. Encouraged private and public sector to implement policies to reduce crash risk for occupants and other road

In this situation, strategic traffic management is a key factor in Intelligent Transport Systems applications. In urban areas, the traffic control center gathers parameters and information

In the literature, three main research lines are the most important: sensor development, applications and improvement of time-of-flight (ToF) techniques. Today, most of the effort is focused on development of the applications. The group of authors working on sensor development focuses on laser optical systems and laser telemetry. In the University of California-Davis, Cheng et al.(Cheng et al., 2005; 2001) developed a laser-based detector using a laser line projected on the ground and the reflected beam is collected and focused onto a photodiode array. Even though this sensor can provide information at speed, it uses two lasers. The weakness of the system is sensor costs are increased by using two transmitters and receivers. A slight error in the laser beam alignment during the installation of the sensors can result in significant errors and further, only one lane can be monitored at a time. The range sensor presented by the University of Central Florida cannot be applied in real-time (Hussain

Other research avenues consider it more important to use well designed and highly reliable commercial products than to work on the development of new sensors and work on improving acquisition and signal treatment without going into sensor technology. This group focuses on the application and represents the majority of the current research (Abdelbaki et al., 2001; Fuerstenberg & Dietmayer, 2004; Gallego et al., 2007; Harlow, 2001; Hussain & Moussa, 2005). Fuerstenberg and Dietmayer (Fuerstenberg & Dietmayer, 2004) investigate sensors installed in vehicles in order to detect moving pedestrians. Hussain and Moussa (Hussain & Moussa, 2005) develop a vehicle classification system called AVCSLII. The classification algorithm was produced by training neural networks and experimental results present five classes based on a database of 4995 vehicles. Harlow and Peng (Harlow, 2001) propose a solution to vehicle detection by processing range imagery. The solution produces different

The authors do not take advantage of the two sweeping laser scan lines to exploit all the potential information, nor do they use the laser scans to measure vehicle speed. The proposal lacks in-depth analysis of speed, requires a larger database and further study under different weather conditions. Lastly, scientists have made a breakthrough in circuit design. It is worth mentioning the research of J. Kostamovaara of the University of Oulu in Helsinki (Palojarvi

classification methods generated by two laser scan lines separated by 10◦.

about real time traffic which are used to implement traffic policies and legislation.

the World Report on Road Traffic Injury Prevention (UN, 2004).

mitigation of their consequences (WHA, 2004).

**1.2 Review of related work: Laser Scanner in ITS systems**

safety (UN, 2005).

users (UN, 2008).

& Moussa, 2005).

the processing and analysis of data received and also, in certain cases, executes the required remedial actions or control strategy.

Since there are a number of sensing technologies relevant to ITS, several studies and reports comparing them have been published (Fang et al., 2007; Klein et al., 2006; Mimbela & Klein, 2007; Skszek, 2001; Turner & Austin, 2000). Inductive loops and magnetic sensors require road closure for their installation and maintenance. The video image processor is vulnerable to weather and light conditions. Ultrasonic and infrared sensors lack stability in noisy environments. Microwave radars are not suitable for vehicle classification (Klein et al., 2006). Laser scanner sensors installation and maintenance do not require road closure, and are more robust and less vulnerable to weather conditions and noisy environments, and are thus the best option for traffic parameter detection.

To solve this situation, a solution is presented to optimize infrastructure sensors already installed in cities, focusing on the case of laser scanners, tackling the problem in two ways: on one hand by developing sensors able to provide more accurate and valuable traffic parameters and on the other by endowing the sensors with "intelligence". These innovations introduce an approach geared towards a new generation of sensors able to cooperate and communicate with the traffic control center (TCC).

The detection system used is a laser scanner, which provides information in real-time about: detection (presence), flow rate, counting and vehicle classification. The classification has been made following statistical methods in eight groups (8+1): powered two-wheels (motorbikes, . . . ), car, car with trailer, van, truck, truck with trailer, artic, bus + unclassified. The intention is to improve traffic management quality by providing supported information about the traffic parameters on the road network.

#### **1.1 State of the art**

Road safety became a global concern with the release of the, "World Report on Road Traffic Injury Prevention" (Peden et al., 2004). This report declares that, *"Of all the systems with which people have to deal every day, road traffic systems are the most complex and the most dangerous. Worldwide, an estimated 1.2 million people are killed in road crashes each year and as many as 50 million are injured. Projections indicate that these figures will increase by about 65% over the next 20 years unless there is new commitment to prevention"*. Some important mistakes were detected, "Insufficient attention to the design of traffic systems" (Peden et al., 2004). This statement confirms the reason to develop and design traffic monitoring systems to help reduce the actual traffic accident rate.

In April 2004, the General Assembly of the United Nations (UN) approved a resolution urging the improvement of road safety in the world (UN, 2004). This assembly invited the World Health Organization (WHO) to coordinate the safety activities within UN organizations. This was the beginning of the, "Road Safety Collaboration Group" with representatives of more than 42 organizations. Key provisions of the UN resolutions related with "Road Safety" are summarized in:

2 Will-be-set-by-IN-TECH

the processing and analysis of data received and also, in certain cases, executes the required

Since there are a number of sensing technologies relevant to ITS, several studies and reports comparing them have been published (Fang et al., 2007; Klein et al., 2006; Mimbela & Klein, 2007; Skszek, 2001; Turner & Austin, 2000). Inductive loops and magnetic sensors require road closure for their installation and maintenance. The video image processor is vulnerable to weather and light conditions. Ultrasonic and infrared sensors lack stability in noisy environments. Microwave radars are not suitable for vehicle classification (Klein et al., 2006). Laser scanner sensors installation and maintenance do not require road closure, and are more robust and less vulnerable to weather conditions and noisy environments, and are thus the

To solve this situation, a solution is presented to optimize infrastructure sensors already installed in cities, focusing on the case of laser scanners, tackling the problem in two ways: on one hand by developing sensors able to provide more accurate and valuable traffic parameters and on the other by endowing the sensors with "intelligence". These innovations introduce an approach geared towards a new generation of sensors able to cooperate and communicate

The detection system used is a laser scanner, which provides information in real-time about: detection (presence), flow rate, counting and vehicle classification. The classification has been made following statistical methods in eight groups (8+1): powered two-wheels (motorbikes, . . . ), car, car with trailer, van, truck, truck with trailer, artic, bus + unclassified. The intention is to improve traffic management quality by providing supported information about the traffic

Road safety became a global concern with the release of the, "World Report on Road Traffic Injury Prevention" (Peden et al., 2004). This report declares that, *"Of all the systems with which people have to deal every day, road traffic systems are the most complex and the most dangerous. Worldwide, an estimated 1.2 million people are killed in road crashes each year and as many as 50 million are injured. Projections indicate that these figures will increase by about 65% over the next 20 years unless there is new commitment to prevention"*. Some important mistakes were detected, "Insufficient attention to the design of traffic systems" (Peden et al., 2004). This statement confirms the reason to develop and design traffic monitoring systems to help reduce the actual

In April 2004, the General Assembly of the United Nations (UN) approved a resolution urging the improvement of road safety in the world (UN, 2004). This assembly invited the World Health Organization (WHO) to coordinate the safety activities within UN organizations. This was the beginning of the, "Road Safety Collaboration Group" with representatives of more than 42 organizations. Key provisions of the UN resolutions related with "Road Safety" are

• May 2003 - UN General Assembly: Global Road Safety crisis. Called on governments and civil society to raise awareness and enforce existing road safety legislation (UN, 2003b). • November 2003 - UN General Assembly: Global Road Safety crisis. Formalized, "Improving road safety" as an agenda item for the 60ˆth General Assembly Session (UN,

remedial actions or control strategy.

best option for traffic parameter detection.

with the traffic control center (TCC).

parameters on the road network.

**1.1 State of the art**

traffic accident rate.

summarized in:

2003a).

In this situation, strategic traffic management is a key factor in Intelligent Transport Systems applications. In urban areas, the traffic control center gathers parameters and information about real time traffic which are used to implement traffic policies and legislation.

#### **1.2 Review of related work: Laser Scanner in ITS systems**

In the literature, three main research lines are the most important: sensor development, applications and improvement of time-of-flight (ToF) techniques. Today, most of the effort is focused on development of the applications. The group of authors working on sensor development focuses on laser optical systems and laser telemetry. In the University of California-Davis, Cheng et al.(Cheng et al., 2005; 2001) developed a laser-based detector using a laser line projected on the ground and the reflected beam is collected and focused onto a photodiode array. Even though this sensor can provide information at speed, it uses two lasers. The weakness of the system is sensor costs are increased by using two transmitters and receivers. A slight error in the laser beam alignment during the installation of the sensors can result in significant errors and further, only one lane can be monitored at a time. The range sensor presented by the University of Central Florida cannot be applied in real-time (Hussain & Moussa, 2005).

Other research avenues consider it more important to use well designed and highly reliable commercial products than to work on the development of new sensors and work on improving acquisition and signal treatment without going into sensor technology. This group focuses on the application and represents the majority of the current research (Abdelbaki et al., 2001; Fuerstenberg & Dietmayer, 2004; Gallego et al., 2007; Harlow, 2001; Hussain & Moussa, 2005). Fuerstenberg and Dietmayer (Fuerstenberg & Dietmayer, 2004) investigate sensors installed in vehicles in order to detect moving pedestrians. Hussain and Moussa (Hussain & Moussa, 2005) develop a vehicle classification system called AVCSLII. The classification algorithm was produced by training neural networks and experimental results present five classes based on a database of 4995 vehicles. Harlow and Peng (Harlow, 2001) propose a solution to vehicle detection by processing range imagery. The solution produces different classification methods generated by two laser scan lines separated by 10◦.

The authors do not take advantage of the two sweeping laser scan lines to exploit all the potential information, nor do they use the laser scans to measure vehicle speed. The proposal lacks in-depth analysis of speed, requires a larger database and further study under different weather conditions. Lastly, scientists have made a breakthrough in circuit design. It is worth mentioning the research of J. Kostamovaara of the University of Oulu in Helsinki (Palojarvi

After the preliminary studies carried out laser scanner system requirements for its use are

Laser Scanner: eSafety & ITS Applications 55

**System Requirements**

shown in Table 1.

**General**

**Scanner**

**Functional**

silhouette of vehicles

altitude of 5 meters

distance of 8191 mm.

Table 1. Technical Requirements

center using Ethernet Communication

**2.2 Laser Scanner measurement and data principle**

**Communications**

located vertically above of the road (m) 5 Maximum Consumption (W) 40 Laser Class I (safe)

Emitter type IR Laser diode

Baudrate (KBd) 9,6 - 500 High speed option (MBd) 1,5

Scanning frequency (HZ) 15 - 100 Response time (ms) 53 - 10 Scanning angle (◦) 100 - 180 Angular resolution (◦) 0,25 - 1 Resolution (mm) 10

Interface RS232 optional RS485/422

The laser scanner system should be able to detect and classify vehicles

The laser scanner system must have direct vision to the lanes

thus it is also important to understand the hardware developed:

• Data format is set as follows: 1 start bit, 8 data bits and 1 stop bit (8N1).

The laser scanner system should be able to allow the acquisition and storage of

The laser scanner system should be located in the vertical of the road to a minimum

The laser scanner system should be able to communicate to the local traffic control

Laser scanner is used in measuring mode (of the distance values). This means that the laser scanner outputs each distance value in two data bytes. In the standard measuring configuration, data bits 0 to 12 are used to represent the distance, while data bits 13 to 15 are not used. These 13 data bits enable 213-1= 8191 coding options to be represented. As we have selected a measured value resolution of 1 mm, this will result in a maximum measuring

The communications with the laser scanner are done through commands. Commands are a set of predefined instructions which carry out different operations like the configuration of the system. The following remarks are important to know how the laser scanner communicates,

et al., 2005; Pehkonen et al., 2006), who investigated and optimized the receiver channel for a pulsed, ToF, laser range finder using BiCMOS technology.

#### **2. System description**

Present Laser Scanners are not designed specifically for traffic control applications, though the few which are do not provide the software needed for signal acquisition and treatment thus none of the actual systems can provide information in real time.

The proposed Laser Scanner System provides a set of sensor (laser scanner), communications and software modules able to detect and classify vehicles in real-time, acquiring and storing their silhouette and 3D image in addition to required traffic parameters.

#### **2.1 Technical requirements**

Laser Scanners measure the ToF of the coherent light coming from an emitter laser, and reflected by the vehicle for its detection. By means of the laser technology, parallel and coherent beams can be generated. A pulsed laser beam is emitted by the laser scanner and reflected by the vehicle. The reflection is registered by the scanner receiver. The time elapsed between the emission and reception of the pulse is directly proportional to the distance between the scanner and the object. For correct vehicle detections the minimum number of readings to identify a vehicle is 20 measurements. Laser scanners measure the time-of-flight of the laser pulse reflected by the vehicle. The laser works in the infrared range, approximate wavelength 0,9 um, which is outside the visible range thus avoiding possible distraction to road users. Furthermore the chosen laser frequency also lies outside the bandwidth of sunlight thereby minimizing this source of interference.

The laser scanner is located at a suitable height above the road to cover all lanes. Therefore the system must be located vertically above of the road with a minimum height of 5 meters, Fig. 1(a). In order to provide the required cross-sectional readings on each vehicle, it is advised to work with angular steps of 1◦, Fig. 1(b). This angle can be increased as long as direct vision to the lanes is guaranteed.

(a) Laser Scanner Positioning (b) Operation Principle

#### Fig. 1. Operation Principle

The communications between sensor and control unit included in the laser scanner system will be done via RS232 using a proprietary protocol. This communication can be implemented using the Ethernet protocol. By means of these specifications, the laser system should be able to detect and classify vehicles; as well as, acquire and store their silhouette.

4 Will-be-set-by-IN-TECH

et al., 2005; Pehkonen et al., 2006), who investigated and optimized the receiver channel for a

Present Laser Scanners are not designed specifically for traffic control applications, though the few which are do not provide the software needed for signal acquisition and treatment thus

The proposed Laser Scanner System provides a set of sensor (laser scanner), communications and software modules able to detect and classify vehicles in real-time, acquiring and storing

Laser Scanners measure the ToF of the coherent light coming from an emitter laser, and reflected by the vehicle for its detection. By means of the laser technology, parallel and coherent beams can be generated. A pulsed laser beam is emitted by the laser scanner and reflected by the vehicle. The reflection is registered by the scanner receiver. The time elapsed between the emission and reception of the pulse is directly proportional to the distance between the scanner and the object. For correct vehicle detections the minimum number of readings to identify a vehicle is 20 measurements. Laser scanners measure the time-of-flight of the laser pulse reflected by the vehicle. The laser works in the infrared range, approximate wavelength 0,9 um, which is outside the visible range thus avoiding possible distraction to road users. Furthermore the chosen laser frequency also lies outside the bandwidth of sunlight

The laser scanner is located at a suitable height above the road to cover all lanes. Therefore the system must be located vertically above of the road with a minimum height of 5 meters, Fig. 1(a). In order to provide the required cross-sectional readings on each vehicle, it is advised to work with angular steps of 1◦, Fig. 1(b). This angle can be increased as long as direct vision to

(a) Laser Scanner Positioning (b) Operation Principle

The communications between sensor and control unit included in the laser scanner system will be done via RS232 using a proprietary protocol. This communication can be implemented using the Ethernet protocol. By means of these specifications, the laser system should be able

to detect and classify vehicles; as well as, acquire and store their silhouette.

pulsed, ToF, laser range finder using BiCMOS technology.

none of the actual systems can provide information in real time.

their silhouette and 3D image in addition to required traffic parameters.

**2. System description**

**2.1 Technical requirements**

the lanes is guaranteed.

Fig. 1. Operation Principle

thereby minimizing this source of interference.

After the preliminary studies carried out laser scanner system requirements for its use are shown in Table 1.

The laser scanner system should be able to detect and classify vehicles

The laser scanner system should be able to allow the acquisition and storage of silhouette of vehicles

The laser scanner system should be located in the vertical of the road to a minimum altitude of 5 meters

The laser scanner system must have direct vision to the lanes

The laser scanner system should be able to communicate to the local traffic control center using Ethernet Communication

Table 1. Technical Requirements

#### **2.2 Laser Scanner measurement and data principle**

Laser scanner is used in measuring mode (of the distance values). This means that the laser scanner outputs each distance value in two data bytes. In the standard measuring configuration, data bits 0 to 12 are used to represent the distance, while data bits 13 to 15 are not used. These 13 data bits enable 213-1= 8191 coding options to be represented. As we have selected a measured value resolution of 1 mm, this will result in a maximum measuring distance of 8191 mm.

The communications with the laser scanner are done through commands. Commands are a set of predefined instructions which carry out different operations like the configuration of the system. The following remarks are important to know how the laser scanner communicates, thus it is also important to understand the hardware developed:

• Data format is set as follows: 1 start bit, 8 data bits and 1 stop bit (8N1).

The first task was to establish communication with the laser scanner sensor. The sensor sends data using the communication standard RS422; it provides a service for data transmission, using balanced or differential signaling. Therefore the first requirement was to develop hardware able to read this information using the computer serial port. For this purpose the hardware unit designed included differential drivers and converters. The differential driver and receiver pair was designed for balanced transmission-line and it is used to convert from RS422-TTL. Later on, another converter from TTL to RS232 level is needed to communicate using the serial port of the computer. The communication was established successfully with the laser scanner sensor. The bidirectional communication required for setting the

Laser Scanner: eSafety & ITS Applications 57

DSP microcontroller is the only solution, because the sensor sends 361 measurements per scan

The signal processing is done in two stages which are in different physical locations. The vehicle detection is done on the DSP and the vehicle classification is done on the computer, using decision trees. Prior to vehicle classification data detected by the laser scanner needs to be pre-treated. This pre-treatment consist of geometric corrections and detection and elimination of static objects on the road. The goal of data normalization is obtain a 3D matrix

Data sent by laser scanner is the distance between the sensor and the vehicle or the detected object. This distance is not perpendicular to the road and is related with the angle, *α*, at which the measurement is taken. Several authors refer to this consideration as geometric correction (Harlow, 2001). Graphically, in Fig. 3, value measured is A, whilst the information needed is the height *h* and the position *x*. By simple mathematics the height of the object h and the

Detection and elimination of static objects on the road is easily implemented by storing an offset vector in absence of vehicles, Fig. 4. This offset vector is subtracted from the laser

scanner data thus ensuring permanent fixtures and road anomalies are eliminated.

configuration was facilitated by means of the sensor commands.

Data received from the laser scanner must be normalized in three steps:

• Geometric corrections, due to data measure by laser scanner.

each 13 ms. The DSP firmware was developed for:

• signal pre-treatment,

**3. Data normalization**

• laser scanner configuration, • and data configuration.

representing detected vehicle.

• Lost reflections.

**3.1 Geometric corrections**

position x can be calculated.

**3.2 Static objects**

• Elimination of static objects on the road.

The next instructions set must be followed in order to configure the laser scanner: baudrate configuration (9600, 38400 or 500K), range configuration (100◦, 180◦), resolution (1◦, 0.5◦, 0.25◦) and measurement units (mm, cm).

#### **2.3 Architecture hardware**

The detector is divided into three parts: the sensor, the control unit, and the software classification program (Gallego et al., 2009). The sensor is installed in the pole of the traffic light. The control unit comprises the hardware and communications module. And lastly, the classification program running on a computer.

The communications between the sensor and the control unit is via RS422. At high speed baudrate communication it is not possible to use serial communication between the control unit and the computer, therefore we have chosen standard USB. This way connection to the computer would be effected using the USB port.

The control unit must: establish communication with the laser scanner, modify the configuration settings and carry out the signal pre-treatment using DSP microcontrollers (Digital Signal Processor). The signal processing is done in two stages which are in different physical locations. The vehicle detection is done on the control unit and the vehicle classification is done on the computer. The final control unit designed is shown in Fig. 2.

(a) HW front (b) HW back

(c) HW connectors

Fig. 2. Hardware Design

6 Will-be-set-by-IN-TECH

• Laser scanner outputs data in ascending angular steps. The angular values themselves are

• Laser scanner is configured by means of commands called telegrams. A send telegram always contains only one control command, and a response telegram contains only one

The next instructions set must be followed in order to configure the laser scanner: baudrate configuration (9600, 38400 or 500K), range configuration (100◦, 180◦), resolution (1◦, 0.5◦,

The detector is divided into three parts: the sensor, the control unit, and the software classification program (Gallego et al., 2009). The sensor is installed in the pole of the traffic light. The control unit comprises the hardware and communications module. And lastly, the

The communications between the sensor and the control unit is via RS422. At high speed baudrate communication it is not possible to use serial communication between the control unit and the computer, therefore we have chosen standard USB. This way connection to the

The control unit must: establish communication with the laser scanner, modify the configuration settings and carry out the signal pre-treatment using DSP microcontrollers (Digital Signal Processor). The signal processing is done in two stages which are in different physical locations. The vehicle detection is done on the control unit and the vehicle classification is done on the computer. The final control unit designed is shown in Fig. 2.

(a) HW front (b) HW back

(c) HW connectors

not transmitted; instead, the data field only comprises distance values.

response from the laser scanner.

0.25◦) and measurement units (mm, cm).

classification program running on a computer.

computer would be effected using the USB port.

**2.3 Architecture hardware**

Fig. 2. Hardware Design

The first task was to establish communication with the laser scanner sensor. The sensor sends data using the communication standard RS422; it provides a service for data transmission, using balanced or differential signaling. Therefore the first requirement was to develop hardware able to read this information using the computer serial port. For this purpose the hardware unit designed included differential drivers and converters. The differential driver and receiver pair was designed for balanced transmission-line and it is used to convert from RS422-TTL. Later on, another converter from TTL to RS232 level is needed to communicate using the serial port of the computer. The communication was established successfully with the laser scanner sensor. The bidirectional communication required for setting the configuration was facilitated by means of the sensor commands.

DSP microcontroller is the only solution, because the sensor sends 361 measurements per scan each 13 ms. The DSP firmware was developed for:

#### **3. Data normalization**

The signal processing is done in two stages which are in different physical locations. The vehicle detection is done on the DSP and the vehicle classification is done on the computer, using decision trees. Prior to vehicle classification data detected by the laser scanner needs to be pre-treated. This pre-treatment consist of geometric corrections and detection and elimination of static objects on the road. The goal of data normalization is obtain a 3D matrix representing detected vehicle.

Data received from the laser scanner must be normalized in three steps:

#### **3.1 Geometric corrections**

Data sent by laser scanner is the distance between the sensor and the vehicle or the detected object. This distance is not perpendicular to the road and is related with the angle, *α*, at which the measurement is taken. Several authors refer to this consideration as geometric correction (Harlow, 2001). Graphically, in Fig. 3, value measured is A, whilst the information needed is the height *h* and the position *x*. By simple mathematics the height of the object h and the position x can be calculated.

#### **3.2 Static objects**

Detection and elimination of static objects on the road is easily implemented by storing an offset vector in absence of vehicles, Fig. 4. This offset vector is subtracted from the laser scanner data thus ensuring permanent fixtures and road anomalies are eliminated.

conclude that in this situation all the erroneous values had a typical characteristic of height lower than one meter. Therefore, by filtering the information the erroneous data, so called lost

Laser Scanner: eSafety & ITS Applications 59

**–** Step one: If there are unknown values between well known values, these known values

**–** Step two: If there are unknown values between two data sets with well known values,

**–** If there is a row in the matrix containing only unknown data, the row is left as it is.

This algorithm is programmed in the DSP firmware. To reduce the processing time only the

Laser scanner sensors that are mounted to the side or over a road may experience two types

Lateral view is an effect that can appear when a large vehicle hides another smaller one. The effect of tall cars blocking other lanes is shown graphically in Fig. 6. In this case a passenger car is almost hidden by a taller bus driving in an adjacent lane. The bus covers the passenger car from the sensor. The sensor detects the car, measurement A, but the next value detected, measurement B, is for the bus, so both detections overlap and cause an undercounting. In order to determine overlaps and solve errors, it is necessary to analyze the matrix with the

of data anomalies: lateral views and the effect of the speed (Klein et al., 2006).

the greater values are copied instead of each of the unknown values.

The following algorithm was used to eliminate the lost reflections:

are copied instead of each of the unknown values.

The corrections after executing the algorithm are shown in Fig. 5.

reflections, are eliminated.

• The matrix is transposed.

Fig. 5. Lost Reflections

isolated vehicle information.

**3.4 Data anomalies**

• For each of the rows of the vehicle matrix:

• For each row repeat steps one and two.

valid vehicle detection data is sent to the computer.

Fig. 3. Geometric Corrections

Fig. 4. Offset Vector

#### **3.3 Lost reflections**

The intensity of reflected sunlight from the road is a critical parameter that affects sensor measurements. Clouds blocking the sun are the most important cause for fast and/or large changes in intensity.

As explained previously, the laser scanner principle of operation is based on the measurement of the ToF. The changes in light intensity produce reflections too weak thus they are not received within the maximum detection time set by the sensor. These changes generate false measurements that can cause the sensor to report misleading data.

This effect is a characteristic of the vehicles most reflective parts i.e. the front and back windows. The light of the laser pulse emitted undergoes a reflection at an angle that does not agree with the detector position, thus the diffuse reflection does not take place in a direction that is advantageous to the detector. Fig. 5 shows the image of a vehicle with lost reflections that can be seen in the front and lateral windows because they show height values among 0 and 200 mm, corresponding to the blue color. In the case of the front window, it is possible to verify the data as the expected received pulse values should be between 1.000 and 1.400 mm, while what it is actually received are lower values due to the lost reflections.

In order to be able to correct these errors due to the intrinsic nature of the operation of the sensor it is necessary to do a depth revision of the detected values. After several studies, we 8 Will-be-set-by-IN-TECH

The intensity of reflected sunlight from the road is a critical parameter that affects sensor measurements. Clouds blocking the sun are the most important cause for fast and/or large

As explained previously, the laser scanner principle of operation is based on the measurement of the ToF. The changes in light intensity produce reflections too weak thus they are not received within the maximum detection time set by the sensor. These changes generate false

This effect is a characteristic of the vehicles most reflective parts i.e. the front and back windows. The light of the laser pulse emitted undergoes a reflection at an angle that does not agree with the detector position, thus the diffuse reflection does not take place in a direction that is advantageous to the detector. Fig. 5 shows the image of a vehicle with lost reflections that can be seen in the front and lateral windows because they show height values among 0 and 200 mm, corresponding to the blue color. In the case of the front window, it is possible to verify the data as the expected received pulse values should be between 1.000 and 1.400 mm,

In order to be able to correct these errors due to the intrinsic nature of the operation of the sensor it is necessary to do a depth revision of the detected values. After several studies, we

measurements that can cause the sensor to report misleading data.

while what it is actually received are lower values due to the lost reflections.

Fig. 3. Geometric Corrections

Fig. 4. Offset Vector

**3.3 Lost reflections**

changes in intensity.

conclude that in this situation all the erroneous values had a typical characteristic of height lower than one meter. Therefore, by filtering the information the erroneous data, so called lost reflections, are eliminated.

The following algorithm was used to eliminate the lost reflections:

	- **–** Step one: If there are unknown values between well known values, these known values are copied instead of each of the unknown values.
	- **–** Step two: If there are unknown values between two data sets with well known values, the greater values are copied instead of each of the unknown values.
	- **–** If there is a row in the matrix containing only unknown data, the row is left as it is.

This algorithm is programmed in the DSP firmware. To reduce the processing time only the valid vehicle detection data is sent to the computer.

The corrections after executing the algorithm are shown in Fig. 5.

Fig. 5. Lost Reflections

#### **3.4 Data anomalies**