Boys start to get acne at the age of approximately 12 years, with a range of 9 to 15 years old. As most girls will attest, boys on average mature later than girls. Early on in the onset of teen acne, the main lesions are blackheads and whiteheads.
The angular size (angular diameter, apparent size) of an object as seen from a given point is the visual diameter of the object measured as an angle. The visual diameter is the diameter of the perspective projection of the object on a plane through its center that is perpendicular to the viewing direction.
1. SPECTRAL RESOLUTION: This refers to the number of bands in the spectrum in which the instrument can take measurements. Landsat TM = 7 channels2. RADIOMETRIC RESOLUTION: This is the sensitivity to small differences in the radiation of an observed object. Landsat TM = 8 bit3. SPATIAL RESOLUTION: This represents the ability of the sensor to detect and distinguish small objects and fine detail in larger objects. Depends on the instrument's sensitivity and distance from the object, and defines the pixel size of a digital image. Landsat TM = 30m4.