GPS , GLONASS , Galileo and BeiDou system are formalizing the balance situation . This paper puts forward strengthening the balance of BeiDou navigation satellite system based on the recommendation of separation . Experiments were conducted using the dual-frequency GPS/Beidou data collected in Wuhan and processed with GPS and Beidou system separately . The preliminary results indicate that the current Beidou system has the ability of precise positioning capacity . For the short baseline(≤ 15 km ) of the Beidou system , the success rate of single epoch ambiguity resolution reaches 80%.The final positioning precision is better than 3 cm on the horizon , and is better than 6 cm for elevation . A method to realize the baseband signal processing of the Beidou/GPS multi-mode receiver is introduced in this paper by using the chip EP2S90F1020I4 , which is Stratix II series of Altera 's FPGA . Using Verilog HDL to design the baseband processing module of Beidou/GPS , including the fast acquisition module and tracking channel processing module , and the tracking channel processing module includes the carrier/code NCO generation module , the complex phase rotation DDC ( Digital Down Converter ) module , the Beidou/GPS pseudo-random code generator , code correlator module and frame synchronization module , etc . Test results show that the baseband signal processing module based on FPGA with the DSP calculation module can achieve the normal PVT calculation . The invention discloses a vehicle stopping timing automatic flameout method and system , and belongs to the field of vehicle flameout control . The method includes the steps that a Beidou/GPS module is utilized to judge the running state of a vehicle , and a single-chip microcomputer central processing unit is utilized to read information transmitted from the Beidou/GPS module ; the single-chip microcomputer central processing unit judges whether the vehicle speed is zero or not , if yes , the single-chip microcomputer central processing unit conducts timing ; if not , the single-chip microcomputer central processing unit does not conduct timing ; the single-chip microcomputer central processing unit judges whether timing is finished or not , if yes , power is supplied to a normally-closed relay to make the vehicle automatically flame out ; if not , timing automatically returns to zero , power is not supplied to the normally-closed relay , and the vehicle can normally run . The invention further discloses the vehicle stopping timing automatic flameout system . Experimental results under the two environments show that the BeiDou system has better positioning performance than the GPS system . Under open environment , both modes of the new method can use fewer satellites to perform better positioning performance than the BeiDou /GPS system . The performance with the second mode is better than that with the first mode . The ground Beidou high-precision time service system comprises a zero level optical fiber network , a first level optical fiber network , a second level optical fiber network and a third level optical fiber network in a setting mode , a level calibration mechanism is adopted for maintaining clock synchronization of the optical fiber networks at all the levels , and a single-fiber bi-direction calibration method is adopted for achieving the clock synchronization of the optical fiber networks at all the levels . The ground Beidou high-precision time service system based on the ground optical fiber networks has the advantages that a ground-based time service system can be formed , the ground-based time service system and a space-based time service system ( such as a GPS/a GLONASS/a Beidou satellite navigation system ) serve as standby mutually and are supported mutually , and the ground Beidou high-precision time service system has the advantages of being low in cost , high in disturbance resistance destroy resistance and the like and provides the most basic time service for China military and civilian communication , navigation and positioning systems . Based on interferometry measurement theory of satellite carrier phase , the technology of land vehicle heading determination through Beidou Bi-Satellite System was studied . Firstly the mathematical model of Beidou heading determination was set up . The test results confirmed the effectiveness of ERMM ambiguity resolution method with the real-time heading determination accuracy reaching 0.62 degree . The research indicates that Beidou Bi-Satellite System can be used to real-time land vehicle heading resolution . Although inertial navigation based orientation finding is completely autonomous , its real-time performance is limited by the accuracy of gyro , and the cost is very high , which is not suitable for low cost applications . An attitude determination system compose of rotation mechanism and multiple Beidou receivers is proposed , which have the advantages from both inertial system and GNSS system . It is a low cost attitude determination system for low dynamic applications . This paper briefly describes the constellation and mathematical model of the Beidou system . Both static and kinematical positioning tests with Beidou receivers were conducted , and the results compared with GPS data . The investigation in the paper shows that the Beidou system can provide navigation and positioning services with an accuracy of below 20 m in an area with calibration stations . This proposed method was illustrated by designing a high-resistivity silicon based patch antenna which is used as RF front in a Beidou receiver . The results showed that the SysML based information from the different diagrams of Beidou receiver and the multidisciplinary design phases can be connected and used during the development of new MEMS product , resulting in shortened development cycles . To avoid exposure , BeiDou System ( BDS ) receiver should not work continually during integrating with Strapdown Inertial Navigation System ( SINS ) . While Doppler Active Radar Seeker ( ARS ) could be aided SINS by beam velocity all the times and remedy the BDS ’s default of lacking velocity information and continual working ability . In this study , we develop a numerical weather model ( NWM ) augmented PPP processing algorithm to improve BeiDou precise positioning . Tropospheric delay parameters , i.e. , zenith delays , mapping functions , and horizontal delay gradients , derived from short-range forecasts from the Global Forecast System of the National Centers for Environmental Prediction ( NCEP ) are applied into BeiDou real-time PPP . Observational data from stations that are capable of tracking the BeiDou constellation from the International GNSS Service ( IGS ) Multi-GNSS Experiments network are processed , with the introduced NWM-augmented PPP and the standard PPP processing . RT PPP with ambiguity resolution based on raw GNSS observations , aided by the satellite clock offsets and GPS un-calibrated phase delays ( UPDs ) , is realized to evaluate the effect of GNSS observations . Compared with previous studies , Galileo observations are integrated in this analysis and the effect of new BeiDou/Galileo systems in RT PPP ambiguity resolution is analyzed for global users . Comparing with the GPS-only and GPS/GLONASS solution , the time to first fix ( TTFF ) is 18.8 % and 7.9 % improved for those users in the Asia-Pacific regions , while it is 9.6 % and 3.8 % improved for other users by adding the BeiDou/Galileo observations . The SF-PPP accuracy and convergence time obtained through the proposed RIMs are computed and compared with those obtained through the international GNSS service global ionospheric maps ( IGS-GIM ) . The results show that the RIMs speed up the convergence time and enhance the overall positioning accuracy in comparison with the IGS-GIM model , particularly the combined GPS/BeiDou-based model . The present invention relates to a method for the location of the message ( 17 ) in a vehicle ad-hoc network between the transmitter ( 8) and the receiver ( 3 ) between the transmission ( 1 ) in the filter , the message comprising at least a transmitter ( 8) ( 12 ) , the method comprising : - by means of a global navigation satellite system ( 11 ) determining the position ( 12 ) a receiver ( 3 ) in a predetermined coordinate system ( 54 ) ; - determining in the receiver ( 3 ) in position ( 12 ) in a predetermined coordinate system ( 54 ) is determined in the receiver ( 3 ) with the transmitter ( 8) between a maximum distance ( 51 ) a threshold determination ( 53 ) ; and - a position ( if the transmitter 12 ( 8) the distance between ( 12 ) the position ) and the receiver ( 3 ) ( 51 ) exceeds a threshold determination ( 53 ) , then the message is discarded ( 17 ) . An in-flight awareness of network morphology and node location is therefore needed . While global navigation satellite systems offer an attractive solution , signal occlusion , spoofing , and jamming present unacceptable vulnerabilities — particularly for mission-critical operations . Alternative network localization methods using inter-agent radio frequency ranging and Angle of Arrival have been well studied over the past 15 years , but existing algorithms are not well suited to fast-moving networks . Global navigation satellite system could provide accurate positioning results in signal complete condition . However , the performance is severe when signal denied , especially for the single-mode BeiDou receiver . The proposed method is applied to a heavy-duty automated guided vehicle for engineering verification . Without multi-path error , the navigation accuracy is 1.8–2.98 times higher than that of the traditional global navigation satellite system navigation . In the case of multi-path error , the improved method still has high fault tolerance and high navigation accuracy . The invention relates to a method for filtering a message ( 17 ) transmitted between a transmitter ( 8) and a receiver ( 3 ) in a vehicular point-to-point network ( 1 ) , said message containing at least one position ( 12 ) of the transmitter ( 8) , comprising the following steps : determining a position ( 12 ) of the receiver ( 3 ) by means of a global satellite navigation system ( 11 ) in a predetermined coordinate system ( 54 ) ; determining a decision threshold ( 53 ) for a maximum distance ( 51 ) between the receiver ( 3 ) and the transmitter ( 8) in the predetermined coordinate system ( 54 ) in which the position ( 12 ) of the receiver ( 3 ) was determined ; and discarding the message ( 17 ) if a distance ( 51 ) between the position ( 12 ) of the transmitter ( 8) and the position ( 12 ) of the receiver ( 3 ) exceeds the decision threshold ( 53 ) . Global satellite navigation systems intended for high precision measurement of coordinates , velocities and time have been widely developed . The study of equipment functional possibilities for users of these systems is of great interest . Today , GNSS ( Global Navigation Satellite System ) systems made their entrance in the transport field through applications such as monitoring of containers or fleet management . These applications do not necessarily request a high availability , integrity and accuracy of the positioning system . Precise corrections with a three-dimensional voxel model of the ionosphere based on Global Navigation Satellite System ( GNSS ) data from a wide-area network of ground receivers can help resolve differential carrier-phase ambiguities over very long baselines of hundreds of kilometers in present two-frequency systems [ Global Positioning System ( GPS ) and Global Orbiting Navigation Satellite System ( GLONASS ) ] or in planned three-frequency systems ( GALILEO , Modernized GPS ) . A study based on simulated three-frequency data from a modified GNSS signal generator indicates that all the phase ambiguities could be resolved successfully more than 90 % of the time . Besides these physical means , an aspect which is almost as important is the associated processing techniques : calculation methods , fusion algorithms , filtering , etc . This leads to our GNSS ( Global Navigation Satellite System ) based approach . The basic idea is to take advantage of the wide availability of such receivers and the strength of the related community of engineers and researchers . However , these climatologies are affected by sampling biases . In Germany , a dense Global Navigation Satellite System network provides accurate IWV measurements not limited by weather conditions and with high temporal resolution . Therefore , they serve as a reference to assess the quality and sampling issues of IWV products from multiple satellite instruments that show different orbital and instrument characteristics . Position determination using satellite navigation system has grown significantly . It provides geospatial with global coverage called GNSS ( Global Navigation System Satellite ) . GNSS satellites consists of GLONASS , GPS ( Global positioning system ) and Galileo . The second step is the development of Galileo as a global , independent , and interoperable satellite-based navigation system . Galileo will be the first global satellite-based navigation system under civil control . GNSS-based navigation technology for lunar mission with more than 60,000 km above earth , which is still lack of relevant research and simulation . In this paper , “ Chang-E One ” lunar mission is used with three stages of orbiting the earth , earth-moon transfer , and around moon . Abstract In the framework of the novel navigation scenario offered by the next generation satellite low thrust autonomous LEO-to-MEO orbit transfer , this study proposes and tests a GNSS based navigation system aimed at providing on-board precise and robust orbit determination strategy to override rising criticalities . The analysis introduces the challenging design issues to simultaneously deal with the variable orbit regime , the electric thrust control and the high orbit GNSS visibility conditions . This approach pursues usability and energy efficiency rather than security , thus leaving the smartphones exposed to potential vulnerabilities . Spoofing attacks are becoming a serious threat to applications that rely on GNSS : building a GNSS spoofer barely requires some basic knowledge and a few hundred euros . Differently from autonomous GNSS receivers , mobile devices have access to redundant positioning information ( Assisted GNSS ( A-GNSS ) , sensors , etc . ) that can be useful for security purposes . First , DOA-based spoof detection makes any spoofing from a single antenna very detectable regardless of how sophisticated its generation . It is difficult for a GNSS spoofer to create different DOAs as it generally requires transmitting from different locations , simultaneously . Thus , it forces a spoofer to utilize a much more complicated transmission system than a single antenna to create signals that can deceive DOA-based spoof detection . Recent research on SDR ( software defined radio ) GNSS receiver is mostly based on DSP/FPGA hybrid or PC platform . In this paper we will introduce a prototype design of SDR GNSS in stand-alone DSP platform . The GNSS receiver with has more than 12 GPS channels , which is implemented in a TI TMS320C6416 DSP chip . This paper presents a scheme for building a deeply coupled GNSS/INS software defined receiver based on Matlab . Two key issues involved , the “ real-time ” calculation and the alignment between GNSS IF data and IMU data , are elaborated in detail . A trigonometric approach to determine the specular reflection point is proposed . Reflection events are simulated assuming different low Earth orbit receivers and GNSS-type transmitters . Suitable events for phase altimetry are assumed between 5 ° and 30 ° elevation lasting between 10 and 15 min with ground tracks length of > 3000 km . The availability of mobility data for scientific analysis has vastly increased , driven by the emergence of inexpensive GNSS recording hardware such as cell phones and small data loggers . Oftentimes , mobility data , which usually contains GNSS coordinates , timestamps , and other sensor measurements , needs to be augmented with additional spatial data in order to derive meaningful information and to facilitate human comprehensibility . In the traditional MEMS-INS/GNSS integration , velocity and position are regarded as measurement information . However , it will lead to unobservable of the heading angle , and the heading angle error will be divergent . The presented approach takes advantage of the flexibility of software-defined radio technology and the forthcoming availability of radiation-hardened , space-certified Systems-on-Module to implement a fully customizable receiver with the capability to process GNSS signals in real-time and to deliver GNSS products in standard formats . The core GNSS engine is based on a free and open source software implementation of a multi-band , multi-system GNSS receiver released under the General Public License v3.0 and available in a public source code repository . These positioning devices are used to determine the satellite unit is shielded absolute and relative positions in the environment , thus allowing seamless transition between the GNSS and the NPS , e.g. outdoors to indoors . Self-positioning-unit device is integrated , thereby allowing effortlessly integrate positioning-unit device to GNSS and NPS network . A benchmark analysis based on a zero baseline is proposed to quantify the stochastic properties . The performance of the consumer grade GNSS receiver is determined and evaluated against geodetic GNSS receivers to better understand the utilization of consumer grade receivers . Results indicate high similarity to the geodetic receiver , even though technical limitations are present . In this contribution , sixty days of BDS-3 clock results were analyzed in terms of their stability and prediction accuracy and compared with the results from BDS-2 ( BDS : BeiDou Navigation Satellite System ) , GPS ( Global Positioning System ) , GLONASS ( Global Navigation Satellite System ) and Galileo clocks . The results show that BDS-3 clocks have greater stability than BDS-2 and BDS-3 s clocks , GPS Block IIA , Block IIR , and Block IIR-M clocks , and GLONASS clocks , while their stability is comparable to that of Block IIF clocks and inferior to that of Galileo clocks . In comparison with the stability of BDS-2 clocks , the percentages of improvement in the stability of BDS-3 clocks range from 5 % to 65 % . To look for the visible satellites , the Parallel Code-Phase Search Acquisition algorithm was used ( PCS ) . Acquisition results for GLONASS G1 are shown and the performance of the receiver is discussed . FIELD : radio engineering , communication . SUBSTANCE : method comprises simultaneously receiving positioning signals for bandwidths of satellite navigation systems : L1 GPS , L1 GLONASS , L2 GPS , L2 GLONASS , L3 GLONASS , L5 GPS . Each used signal is re-emitted by a separate frequency-selective relay which selects , using a band-pass filter , only the bandwidth used by a receiving and a radiating antenna . The paper describes in detail the project development and the results achieved . An analysis of the results , showing that aircraft positioning with GPS/GLONASS augmentation in a local area augmentation system ( LAAS ) scenario can achieve accuracies that are both comparable with GPS-alone solutions and can satisfy up to CAT II precision approach criteria , is presented . Results are also given for position propagation using velocities derived from GPS and GLONASS carrier phase measurements . The big dipper-based high-dynamic three-mode satellite receiver device comprises a radio frequency channel , an antenna , a low noise amplifier , a base-band processing module , a power supply and a whole machine mechanism . The antenna is a BD , GPS and GLONASS three-frequency reception antenna , and the low noise amplifier is arranged inside the antenna and comprises a BD , GPS and GLONASS low noise amplifier to amplify a satellite signal received by the antenna . The radio frequency channel comprises a BD , GPS and GLONASS compatible reception channel , and the base-band processing module comprises a baseband signal transformation module , an information processing module and an application processing module . Due to the adoption of Frequency Division Multiple Access ( FDMA ) , Globalnaya Navigazionnaya Sputnikovaya Sistema ( GLONASS ) code observations are affected by the Inter-Frequency Code Biases ( IFCBs ) , which makes it difficult to calculate the Differential Inter-System Code Biases ( DISCBs ) between GLONASS and the Code Division Multiple Access ( CDMA ) systems directly . In this contribution , the focus is on the performance of tightly combined Global Positioning System ( GPS ) and GLONASS code Double Difference ( DD ) positioning . After analysing the relationship between IFCBs and GLONASS channel numbers , an IFCB correction model and an inter-system code differencing model between GLONASS and GPS are proposed . Finally , the ambiguity-resolved solutions are achieved by introducing the constraints of the resolved ambiguities into the real-valued solutions . To prove the contribution of the AR to GPS and GLONASS POD , a network including 141 sites is processed over 2018 . The results show that the receiver types and firmware versions seriously affect the stability of the daily wide-lane FCBs . Alignment of Coordinate Systems Used by Various Information Technologies to Refine the Geocenter ’s Position . The article considers the problem of improving the coordinate-time support of GLONASS , which implies refining the models of a wide range of stochastic error components caused by inaccurate knowledge of geodetic and geodynamic parameters , such as the position and displacement rate of the geocenter , Universal Time , pole shift , irregularities of the Earth ’s rotation , precession , and nutation . It is shown that the problem can be solved only using a comprehensive measurement technique that includes the use of various information measurement “ techniques , ” namely , global navigation satellite systems , quantum-optical communication stations , Doppler velocity sensors , and very-long-baseline radio interferometers . SUMMARY Processing GLONASS data for geodynamics study The application of two ( or more ) global positioning systems offers many practical benefits . In recent times , outside the GPS , GLONASS system was developed , to meet the surveying , navigation requirements , so the GLONASS data processing has become necessary . In this paper , some GLONASS data of IGS sites have been processed by Bernese software . From the analysis it emerges that Galileo measurements have accuracies comparable with those of GPS . The benefits of combined GPS-Galileo positioning are also highlighted and results relative to the computation of a Galileo-only navigation solution based on broadcast ephemerides are provided . Some significant features of the Galileo system are outlined , including constellation design , and some areas are identified in which Galileo will influence IGS operations in the future and in which the IGS and its active elements can continue to contribute to new GNSS developments . These include the IGS GNSS Working Group , the Galileo System Test Bed GSTB-V2 and the Galileo Geodetic Service Provider ( GGSP ) Prototype . I Background The Galileo Geodetic Service Provider ( GGSP ) prototype • Is a project funded through the sixth Framework Programme for Research and Technological Development of the European Union . • Started in July 2005 and will be finished in May 2009 . Anti-jamming techniques to improve Global Positioning System ( GPS ) receiver 's robustness have been mainly developed in military applications . None of civilian techniques can procure sufficient robustness against occasional or intentional jammers for civil GPS or GALILEO navigation receivers . The amplitude domain processing ( ADP ) filtering is a technique based upon Capon works and Neyman-Pearson theory . All of these papers have dealt with the use of either the Russian GLONASS system or the proposed Galileo system for augmentation of GPS . In this paper , GPS alone will be compared with both Galileo alone and a combined GPS/Galileo system . Galileo Constellation The Galileo System is still in the definition phase and a final constellation design has not yet been made public . In this paper the absolute calibration of GPS time receivers with a Spirent GPS/Galileo HW simulator is analyzed and described in detail . The primary step is to calibrate the simulator itself . The scope of this paper is to describe the approach followed on Copernicus Sentinel-1 C&D satellites to predict , by EM modeling tools : 1 ) the electric field levels generated by , and , on-board equipment inside the satellite cavity and , 2 ) the associated interfering power coupled to the victim antenna . The proposed approach has been implemented by the GALILEO-EMT[1 ] and can be also effectively extended to other frequency ranges using the proper electromagnetic solver suitable for each frequency band . The European GNSS , Galileo is currently in its In-Orbit Validation ( IOV ) phase where four satellites are available for computing the user position . Galileo El OS and GPS C/A represent a very effective constellation pair in a consumer grade receiver : the signals are conveyed on the same analog path and measurements can be combined in a single position , velocity and time ( PVT ) solution , provided that the Galileo to GPS Time Offset ( GGTO ) is available . Algorithms for GGTO estimation are presented in this paper , including a real-time implementation on a compact hardware receiver , based on the Teseo-II chipset . Is introduced the scalar- vector potential , in which the scalar potential of charge and its field they depend on speed . Within the framework the Galileo conversions are obtained conversions pour on upon transfer of one inertial to another . Are examined the bases of trans-coordinate electrodynamics in time-spatial giperkontinuum . To reduce hardware design costs for this pre-production prototype development , the design was demonstrated at the L5/E5a frequency . No commercial Galileo hardware simulators are currently available to test the receiver . NovAtel modified an L5 signal transmitter , developed by NovAtel for Zeta Associates of Fairfax , Virginia , to output BOC(1,1 ) and BPSK(1 ) test signals .
GPS , GLONASS , Galileo and BeiDou system are formalizing the balance situation . This paper puts forward strengthening the balance of BeiDou navigation satellite system based on the recommendation of separation .
Experiments were conducted using the dual-frequency GPS/Beidou data collected in Wuhan and processed with GPS and Beidou system separately . The preliminary results indicate that the current Beidou system has the ability of precise positioning capacity . For the short baseline(≤ 15 km ) of the Beidou system , the success rate of single epoch ambiguity resolution reaches 80%.The final positioning precision is better than 3 cm on the horizon , and is better than 6 cm for elevation .
A method to realize the baseband signal processing of the Beidou/GPS multi-mode receiver is introduced in this paper by using the chip EP2S90F1020I4 , which is Stratix II series of Altera 's FPGA . Using Verilog HDL to design the baseband processing module of Beidou/GPS , including the fast acquisition module and tracking channel processing module , and the tracking channel processing module includes the carrier/code NCO generation module , the complex phase rotation DDC ( Digital Down Converter ) module , the Beidou/GPS pseudo-random code generator , code correlator module and frame synchronization module , etc . Test results show that the baseband signal processing module based on FPGA with the DSP calculation module can achieve the normal PVT calculation .
The invention discloses a vehicle stopping timing automatic flameout method and system , and belongs to the field of vehicle flameout control . The method includes the steps that a Beidou/GPS module is utilized to judge the running state of a vehicle , and a single-chip microcomputer central processing unit is utilized to read information transmitted from the Beidou/GPS module ; the single-chip microcomputer central processing unit judges whether the vehicle speed is zero or not , if yes , the single-chip microcomputer central processing unit conducts timing ; if not , the single-chip microcomputer central processing unit does not conduct timing ; the single-chip microcomputer central processing unit judges whether timing is finished or not , if yes , power is supplied to a normally-closed relay to make the vehicle automatically flame out ; if not , timing automatically returns to zero , power is not supplied to the normally-closed relay , and the vehicle can normally run . The invention further discloses the vehicle stopping timing automatic flameout system .
Experimental results under the two environments show that the BeiDou system has better positioning performance than the GPS system . Under open environment , both modes of the new method can use fewer satellites to perform better positioning performance than the BeiDou /GPS system . The performance with the second mode is better than that with the first mode .
The ground Beidou high-precision time service system comprises a zero level optical fiber network , a first level optical fiber network , a second level optical fiber network and a third level optical fiber network in a setting mode , a level calibration mechanism is adopted for maintaining clock synchronization of the optical fiber networks at all the levels , and a single-fiber bi-direction calibration method is adopted for achieving the clock synchronization of the optical fiber networks at all the levels . The ground Beidou high-precision time service system based on the ground optical fiber networks has the advantages that a ground-based time service system can be formed , the ground-based time service system and a space-based time service system ( such as a GPS/a GLONASS/a Beidou satellite navigation system ) serve as standby mutually and are supported mutually , and the ground Beidou high-precision time service system has the advantages of being low in cost , high in disturbance resistance destroy resistance and the like and provides the most basic time service for China military and civilian communication , navigation and positioning systems .
Based on interferometry measurement theory of satellite carrier phase , the technology of land vehicle heading determination through Beidou Bi-Satellite System was studied . Firstly the mathematical model of Beidou heading determination was set up .
The test results confirmed the effectiveness of ERMM ambiguity resolution method with the real-time heading determination accuracy reaching 0.62 degree . The research indicates that Beidou Bi-Satellite System can be used to real-time land vehicle heading resolution .
Although inertial navigation based orientation finding is completely autonomous , its real-time performance is limited by the accuracy of gyro , and the cost is very high , which is not suitable for low cost applications . An attitude determination system compose of rotation mechanism and multiple Beidou receivers is proposed , which have the advantages from both inertial system and GNSS system . It is a low cost attitude determination system for low dynamic applications .
This paper briefly describes the constellation and mathematical model of the Beidou system . Both static and kinematical positioning tests with Beidou receivers were conducted , and the results compared with GPS data . The investigation in the paper shows that the Beidou system can provide navigation and positioning services with an accuracy of below 20 m in an area with calibration stations .
This proposed method was illustrated by designing a high-resistivity silicon based patch antenna which is used as RF front in a Beidou receiver . The results showed that the SysML based information from the different diagrams of Beidou receiver and the multidisciplinary design phases can be connected and used during the development of new MEMS product , resulting in shortened development cycles .
To avoid exposure , BeiDou System ( BDS ) receiver should not work continually during integrating with Strapdown Inertial Navigation System ( SINS ) . While Doppler Active Radar Seeker ( ARS ) could be aided SINS by beam velocity all the times and remedy the BDS ’s default of lacking velocity information and continual working ability .
In this study , we develop a numerical weather model ( NWM ) augmented PPP processing algorithm to improve BeiDou precise positioning . Tropospheric delay parameters , i.e. , zenith delays , mapping functions , and horizontal delay gradients , derived from short-range forecasts from the Global Forecast System of the National Centers for Environmental Prediction ( NCEP ) are applied into BeiDou real-time PPP . Observational data from stations that are capable of tracking the BeiDou constellation from the International GNSS Service ( IGS ) Multi-GNSS Experiments network are processed , with the introduced NWM-augmented PPP and the standard PPP processing .
RT PPP with ambiguity resolution based on raw GNSS observations , aided by the satellite clock offsets and GPS un-calibrated phase delays ( UPDs ) , is realized to evaluate the effect of GNSS observations . Compared with previous studies , Galileo observations are integrated in this analysis and the effect of new BeiDou/Galileo systems in RT PPP ambiguity resolution is analyzed for global users . Comparing with the GPS-only and GPS/GLONASS solution , the time to first fix ( TTFF ) is 18.8 % and 7.9 % improved for those users in the Asia-Pacific regions , while it is 9.6 % and 3.8 % improved for other users by adding the BeiDou/Galileo observations .
The SF-PPP accuracy and convergence time obtained through the proposed RIMs are computed and compared with those obtained through the international GNSS service global ionospheric maps ( IGS-GIM ) . The results show that the RIMs speed up the convergence time and enhance the overall positioning accuracy in comparison with the IGS-GIM model , particularly the combined GPS/BeiDou-based model .
The present invention relates to a method for the location of the message ( 17 ) in a vehicle ad-hoc network between the transmitter ( 8) and the receiver ( 3 ) between the transmission ( 1 ) in the filter , the message comprising at least a transmitter ( 8) ( 12 ) , the method comprising : - by means of a global navigation satellite system ( 11 ) determining the position ( 12 ) a receiver ( 3 ) in a predetermined coordinate system ( 54 ) ; - determining in the receiver ( 3 ) in position ( 12 ) in a predetermined coordinate system ( 54 ) is determined in the receiver ( 3 ) with the transmitter ( 8) between a maximum distance ( 51 ) a threshold determination ( 53 ) ; and - a position ( if the transmitter 12 ( 8) the distance between ( 12 ) the position ) and the receiver ( 3 ) ( 51 ) exceeds a threshold determination ( 53 ) , then the message is discarded ( 17 ) .
An in-flight awareness of network morphology and node location is therefore needed . While global navigation satellite systems offer an attractive solution , signal occlusion , spoofing , and jamming present unacceptable vulnerabilities — particularly for mission-critical operations . Alternative network localization methods using inter-agent radio frequency ranging and Angle of Arrival have been well studied over the past 15 years , but existing algorithms are not well suited to fast-moving networks .
Global navigation satellite system could provide accurate positioning results in signal complete condition . However , the performance is severe when signal denied , especially for the single-mode BeiDou receiver .
The proposed method is applied to a heavy-duty automated guided vehicle for engineering verification . Without multi-path error , the navigation accuracy is 1.8–2.98 times higher than that of the traditional global navigation satellite system navigation . In the case of multi-path error , the improved method still has high fault tolerance and high navigation accuracy .
The invention relates to a method for filtering a message ( 17 ) transmitted between a transmitter ( 8) and a receiver ( 3 ) in a vehicular point-to-point network ( 1 ) , said message containing at least one position ( 12 ) of the transmitter ( 8) , comprising the following steps : determining a position ( 12 ) of the receiver ( 3 ) by means of a global satellite navigation system ( 11 ) in a predetermined coordinate system ( 54 ) ; determining a decision threshold ( 53 ) for a maximum distance ( 51 ) between the receiver ( 3 ) and the transmitter ( 8) in the predetermined coordinate system ( 54 ) in which the position ( 12 ) of the receiver ( 3 ) was determined ; and discarding the message ( 17 ) if a distance ( 51 ) between the position ( 12 ) of the transmitter ( 8) and the position ( 12 ) of the receiver ( 3 ) exceeds the decision threshold ( 53 ) .
Global satellite navigation systems intended for high precision measurement of coordinates , velocities and time have been widely developed . The study of equipment functional possibilities for users of these systems is of great interest .
Today , GNSS ( Global Navigation Satellite System ) systems made their entrance in the transport field through applications such as monitoring of containers or fleet management . These applications do not necessarily request a high availability , integrity and accuracy of the positioning system .
Precise corrections with a three-dimensional voxel model of the ionosphere based on Global Navigation Satellite System ( GNSS ) data from a wide-area network of ground receivers can help resolve differential carrier-phase ambiguities over very long baselines of hundreds of kilometers in present two-frequency systems [ Global Positioning System ( GPS ) and Global Orbiting Navigation Satellite System ( GLONASS ) ] or in planned three-frequency systems ( GALILEO , Modernized GPS ) . A study based on simulated three-frequency data from a modified GNSS signal generator indicates that all the phase ambiguities could be resolved successfully more than 90 % of the time .
Besides these physical means , an aspect which is almost as important is the associated processing techniques : calculation methods , fusion algorithms , filtering , etc . This leads to our GNSS ( Global Navigation Satellite System ) based approach . The basic idea is to take advantage of the wide availability of such receivers and the strength of the related community of engineers and researchers .
However , these climatologies are affected by sampling biases . In Germany , a dense Global Navigation Satellite System network provides accurate IWV measurements not limited by weather conditions and with high temporal resolution . Therefore , they serve as a reference to assess the quality and sampling issues of IWV products from multiple satellite instruments that show different orbital and instrument characteristics .
Position determination using satellite navigation system has grown significantly . It provides geospatial with global coverage called GNSS ( Global Navigation System Satellite ) . GNSS satellites consists of GLONASS , GPS ( Global positioning system ) and Galileo .
The second step is the development of Galileo as a global , independent , and interoperable satellite-based navigation system . Galileo will be the first global satellite-based navigation system under civil control .
GNSS-based navigation technology for lunar mission with more than 60,000 km above earth , which is still lack of relevant research and simulation . In this paper , “ Chang-E One ” lunar mission is used with three stages of orbiting the earth , earth-moon transfer , and around moon .
Abstract In the framework of the novel navigation scenario offered by the next generation satellite low thrust autonomous LEO-to-MEO orbit transfer , this study proposes and tests a GNSS based navigation system aimed at providing on-board precise and robust orbit determination strategy to override rising criticalities . The analysis introduces the challenging design issues to simultaneously deal with the variable orbit regime , the electric thrust control and the high orbit GNSS visibility conditions .
This approach pursues usability and energy efficiency rather than security , thus leaving the smartphones exposed to potential vulnerabilities . Spoofing attacks are becoming a serious threat to applications that rely on GNSS : building a GNSS spoofer barely requires some basic knowledge and a few hundred euros . Differently from autonomous GNSS receivers , mobile devices have access to redundant positioning information ( Assisted GNSS ( A-GNSS ) , sensors , etc . ) that can be useful for security purposes .
First , DOA-based spoof detection makes any spoofing from a single antenna very detectable regardless of how sophisticated its generation . It is difficult for a GNSS spoofer to create different DOAs as it generally requires transmitting from different locations , simultaneously . Thus , it forces a spoofer to utilize a much more complicated transmission system than a single antenna to create signals that can deceive DOA-based spoof detection .
Recent research on SDR ( software defined radio ) GNSS receiver is mostly based on DSP/FPGA hybrid or PC platform . In this paper we will introduce a prototype design of SDR GNSS in stand-alone DSP platform . The GNSS receiver with has more than 12 GPS channels , which is implemented in a TI TMS320C6416 DSP chip .
This paper presents a scheme for building a deeply coupled GNSS/INS software defined receiver based on Matlab . Two key issues involved , the “ real-time ” calculation and the alignment between GNSS IF data and IMU data , are elaborated in detail .
A trigonometric approach to determine the specular reflection point is proposed . Reflection events are simulated assuming different low Earth orbit receivers and GNSS-type transmitters . Suitable events for phase altimetry are assumed between 5 ° and 30 ° elevation lasting between 10 and 15 min with ground tracks length of > 3000 km .
The availability of mobility data for scientific analysis has vastly increased , driven by the emergence of inexpensive GNSS recording hardware such as cell phones and small data loggers . Oftentimes , mobility data , which usually contains GNSS coordinates , timestamps , and other sensor measurements , needs to be augmented with additional spatial data in order to derive meaningful information and to facilitate human comprehensibility .
In the traditional MEMS-INS/GNSS integration , velocity and position are regarded as measurement information . However , it will lead to unobservable of the heading angle , and the heading angle error will be divergent .
The presented approach takes advantage of the flexibility of software-defined radio technology and the forthcoming availability of radiation-hardened , space-certified Systems-on-Module to implement a fully customizable receiver with the capability to process GNSS signals in real-time and to deliver GNSS products in standard formats . The core GNSS engine is based on a free and open source software implementation of a multi-band , multi-system GNSS receiver released under the General Public License v3.0 and available in a public source code repository .
These positioning devices are used to determine the satellite unit is shielded absolute and relative positions in the environment , thus allowing seamless transition between the GNSS and the NPS , e.g. outdoors to indoors . Self-positioning-unit device is integrated , thereby allowing effortlessly integrate positioning-unit device to GNSS and NPS network .
A benchmark analysis based on a zero baseline is proposed to quantify the stochastic properties . The performance of the consumer grade GNSS receiver is determined and evaluated against geodetic GNSS receivers to better understand the utilization of consumer grade receivers . Results indicate high similarity to the geodetic receiver , even though technical limitations are present .
In this contribution , sixty days of BDS-3 clock results were analyzed in terms of their stability and prediction accuracy and compared with the results from BDS-2 ( BDS : BeiDou Navigation Satellite System ) , GPS ( Global Positioning System ) , GLONASS ( Global Navigation Satellite System ) and Galileo clocks . The results show that BDS-3 clocks have greater stability than BDS-2 and BDS-3 s clocks , GPS Block IIA , Block IIR , and Block IIR-M clocks , and GLONASS clocks , while their stability is comparable to that of Block IIF clocks and inferior to that of Galileo clocks . In comparison with the stability of BDS-2 clocks , the percentages of improvement in the stability of BDS-3 clocks range from 5 % to 65 % .
To look for the visible satellites , the Parallel Code-Phase Search Acquisition algorithm was used ( PCS ) . Acquisition results for GLONASS G1 are shown and the performance of the receiver is discussed .
FIELD : radio engineering , communication . SUBSTANCE : method comprises simultaneously receiving positioning signals for bandwidths of satellite navigation systems : L1 GPS , L1 GLONASS , L2 GPS , L2 GLONASS , L3 GLONASS , L5 GPS . Each used signal is re-emitted by a separate frequency-selective relay which selects , using a band-pass filter , only the bandwidth used by a receiving and a radiating antenna .
The paper describes in detail the project development and the results achieved . An analysis of the results , showing that aircraft positioning with GPS/GLONASS augmentation in a local area augmentation system ( LAAS ) scenario can achieve accuracies that are both comparable with GPS-alone solutions and can satisfy up to CAT II precision approach criteria , is presented . Results are also given for position propagation using velocities derived from GPS and GLONASS carrier phase measurements .
The big dipper-based high-dynamic three-mode satellite receiver device comprises a radio frequency channel , an antenna , a low noise amplifier , a base-band processing module , a power supply and a whole machine mechanism . The antenna is a BD , GPS and GLONASS three-frequency reception antenna , and the low noise amplifier is arranged inside the antenna and comprises a BD , GPS and GLONASS low noise amplifier to amplify a satellite signal received by the antenna . The radio frequency channel comprises a BD , GPS and GLONASS compatible reception channel , and the base-band processing module comprises a baseband signal transformation module , an information processing module and an application processing module .
Due to the adoption of Frequency Division Multiple Access ( FDMA ) , Globalnaya Navigazionnaya Sputnikovaya Sistema ( GLONASS ) code observations are affected by the Inter-Frequency Code Biases ( IFCBs ) , which makes it difficult to calculate the Differential Inter-System Code Biases ( DISCBs ) between GLONASS and the Code Division Multiple Access ( CDMA ) systems directly . In this contribution , the focus is on the performance of tightly combined Global Positioning System ( GPS ) and GLONASS code Double Difference ( DD ) positioning . After analysing the relationship between IFCBs and GLONASS channel numbers , an IFCB correction model and an inter-system code differencing model between GLONASS and GPS are proposed .
Finally , the ambiguity-resolved solutions are achieved by introducing the constraints of the resolved ambiguities into the real-valued solutions . To prove the contribution of the AR to GPS and GLONASS POD , a network including 141 sites is processed over 2018 . The results show that the receiver types and firmware versions seriously affect the stability of the daily wide-lane FCBs .
Alignment of Coordinate Systems Used by Various Information Technologies to Refine the Geocenter ’s Position . The article considers the problem of improving the coordinate-time support of GLONASS , which implies refining the models of a wide range of stochastic error components caused by inaccurate knowledge of geodetic and geodynamic parameters , such as the position and displacement rate of the geocenter , Universal Time , pole shift , irregularities of the Earth ’s rotation , precession , and nutation . It is shown that the problem can be solved only using a comprehensive measurement technique that includes the use of various information measurement “ techniques , ” namely , global navigation satellite systems , quantum-optical communication stations , Doppler velocity sensors , and very-long-baseline radio interferometers .
SUMMARY Processing GLONASS data for geodynamics study The application of two ( or more ) global positioning systems offers many practical benefits . In recent times , outside the GPS , GLONASS system was developed , to meet the surveying , navigation requirements , so the GLONASS data processing has become necessary . In this paper , some GLONASS data of IGS sites have been processed by Bernese software .
From the analysis it emerges that Galileo measurements have accuracies comparable with those of GPS . The benefits of combined GPS-Galileo positioning are also highlighted and results relative to the computation of a Galileo-only navigation solution based on broadcast ephemerides are provided .
Some significant features of the Galileo system are outlined , including constellation design , and some areas are identified in which Galileo will influence IGS operations in the future and in which the IGS and its active elements can continue to contribute to new GNSS developments . These include the IGS GNSS Working Group , the Galileo System Test Bed GSTB-V2 and the Galileo Geodetic Service Provider ( GGSP ) Prototype .
I Background The Galileo Geodetic Service Provider ( GGSP ) prototype • Is a project funded through the sixth Framework Programme for Research and Technological Development of the European Union . • Started in July 2005 and will be finished in May 2009 .
Anti-jamming techniques to improve Global Positioning System ( GPS ) receiver 's robustness have been mainly developed in military applications . None of civilian techniques can procure sufficient robustness against occasional or intentional jammers for civil GPS or GALILEO navigation receivers . The amplitude domain processing ( ADP ) filtering is a technique based upon Capon works and Neyman-Pearson theory .
All of these papers have dealt with the use of either the Russian GLONASS system or the proposed Galileo system for augmentation of GPS . In this paper , GPS alone will be compared with both Galileo alone and a combined GPS/Galileo system . Galileo Constellation The Galileo System is still in the definition phase and a final constellation design has not yet been made public .
In this paper the absolute calibration of GPS time receivers with a Spirent GPS/Galileo HW simulator is analyzed and described in detail . The primary step is to calibrate the simulator itself .
The scope of this paper is to describe the approach followed on Copernicus Sentinel-1 C&D satellites to predict , by EM modeling tools : 1 ) the electric field levels generated by , and , on-board equipment inside the satellite cavity and , 2 ) the associated interfering power coupled to the victim antenna . The proposed approach has been implemented by the GALILEO-EMT[1 ] and can be also effectively extended to other frequency ranges using the proper electromagnetic solver suitable for each frequency band .
The European GNSS , Galileo is currently in its In-Orbit Validation ( IOV ) phase where four satellites are available for computing the user position . Galileo El OS and GPS C/A represent a very effective constellation pair in a consumer grade receiver : the signals are conveyed on the same analog path and measurements can be combined in a single position , velocity and time ( PVT ) solution , provided that the Galileo to GPS Time Offset ( GGTO ) is available . Algorithms for GGTO estimation are presented in this paper , including a real-time implementation on a compact hardware receiver , based on the Teseo-II chipset .
Is introduced the scalar- vector potential , in which the scalar potential of charge and its field they depend on speed . Within the framework the Galileo conversions are obtained conversions pour on upon transfer of one inertial to another . Are examined the bases of trans-coordinate electrodynamics in time-spatial giperkontinuum .
To reduce hardware design costs for this pre-production prototype development , the design was demonstrated at the L5/E5a frequency . No commercial Galileo hardware simulators are currently available to test the receiver . NovAtel modified an L5 signal transmitter , developed by NovAtel for Zeta Associates of Fairfax , Virginia , to output BOC(1,1 ) and BPSK(1 ) test signals .
Balance Recommendations for Compacting BeiDou Navigation Satellite System Preliminary Results of Single Epoch Baseline Solution Based on Beidou Navigation Satellite System Realization of baseband signal processing for Beidou/GPS multi-mode receiver by FPGA Vehicle stopping timing automatic flameout method and system BeiDou /GPS combination positioning methodology Ground Beidou high-precision time service system based on ground optical fiber networks Research on Vehicle Heading Determination through Beidou Bi-satellite System Attitude Determination System Based on Rotation Mechanism and Beidou Reiceivers The Beidou Satellite Positioning System and Its Positioning Accuracy A SysML Based Conceptual Framework for System Level Design in Micromechanical Electrical System Simulation of Navigation Performance Analysis of SINS/BDS Based on ARS Aidance Improving BeiDou real-time precise point positioning with numerical weather models Accelerating real-time PPP ambiguity resolution by incorporating multi-GNSS observations An accurate Kriging-based regional ionospheric model using combined GPS/BeiDou observations X filtered receivers based on geographic coordinates of the vehicle receiving zone Non-Iterative MDS Method for Collaborative Network Localization With Sparse Range and Pointing Measurements A dual-satellite GNSS positioning algorithm of high accuracy in incomplete condition An improved integrated navigation method based on RINS, GNSS and kinematics for port heavy-duty AGV Car-to-X receiver filtering based on a receiving corridor in a geographic coordinate system Algorithms of measuring the angular coordinates of objects with an unknown baseline on the basis of global satellite navigation systems Gnss performance enhancement in urban environment based on pseudo-range error model Feasibility of wide-area subdecimeter navigation with GALILEO and Modernized GPS A GNSS-based inverted radar for carrier phase absolute indoor positioning purposes first experimental results with GPS signals Assessment of Sampling Effects on Various Satellite-Derived Integrated Water Vapor Datasets Using GPS Measurements in Germany as Reference Integration of GNSS-IMU for increasing the observation accuracy in Condensed Areas (Infrastructure and Forest Canopies) European satellite navigation - a challenge Analysis of GNSS Signals with Application to Lunar Navigation On-board orbit determination for low thrust LEO-MEO transfer by Consider Kalman Filtering and multi-constellation GNSS Exploiting side-information for resilient GNSS positioning in mobile phones Accommodating Direction Ambiguities in Direction of Arrival based GNSS Spoof Detection SDR GNSS Receiver Design over Stand-Alone Generic TI DSP Platform An approach for the deeply coupled GNSS/INS software defined receiver based on Matlab A Phase-Altimetric Simulator: Studying the Sensitivity of Earth-Reflected GNSS Signals to Ocean Topography MAGIS – A Geographic Information System for Mobility Data Analysis A Heading Angle Estimation Approach for MEMS-INS/GNSS Integration Based on ZHVC and SAUKF A Software-Defined Spaceborne GNSS Receiver Method and device for creating network positioning system (NPS) Feasibility of Consumer Grade GNSS Receivers for the Integration in Multi-Sensor-Systems Assessment of the BDS-3 on-board clocks and their impact on the PPP time transfer performance Experimental Validation of a Reconfigurable GLONASS Sub-Sampling Receiver Method and system for multifrequency positioning in shielded space Combined GPS/GLONASS LAAS flight trials Big dipper-based high-dynamic three-mode satellite receiver device Tightly combined GPS + GLONASS positioning with consideration of inter-system code bias and GLONASS inter-frequency code bias Combined precise orbit determination of GPS and GLONASS with ambiguity resolution Current Problems of Improving the Coordinate-Time Support of GLONASS and Promising Methods for Their Solution. 1. Alignment of Coordinate Systems Used by Various Information Technologies to Refine the Geocenter’s Position Xử lý số liệu GLONASS phục vụ nghiên cứu địa động lực Testing the test satellites: the Galileo IOV measurement accuracy Galileo and the IGS: Taking advantage of multiple GNSS constellations The Realisation and Validation of the Galileo Terrestrial Reference Frame (GTRF) New anti-jamming technique for GPS and GALILEO receivers using adaptive FADP filter Availability and Reliability Advantages of GPS/Galileo Integration Using of spirent GPS/Galileo HW simulator for timing receiver calibration Effect of RF spurious radiation from units on a satellite VHF receiver Estimation of the GPS to Galileo time offset and its validation on a mass market receiver New ideology in classical electrodynamics Galileo BOC(1,1) Prototype Receiver Development
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IPIN PLANS ITSC SmartNets ICL-GNSS
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