remotely-sensed datasets Flashcards
two types of scanners
across track and along-track
aka across track
whiskbroom
aka along track
pushbroom
what mirror is used by across-track scanner (whiskbroom)
rotating/oscilliating mirror
how does the across-track scanner (whiskbroom) scan the terrain
along scan lines at right angles to flight line
what is the typical angle of arc below the aircraft for data collection in across-track scanner (whiskbroom)
90 to 120 degrees
describe how energy is processed in across-track scanner (whiskbroom)
incoming energy is separated into several components, sensed independently
cone of angle within which incident energy is focused on the detector in across-track scanner (whiskbroom)
IFOV
what does IFOV mean
instantaneous field of view
what the scanner sees
IFOV
equation for diameter of circular ground area viewed in across-track scanner (whiskbroom)
D = H’ B
D = diameter of circular ground area
H’ = flying height
B = IFOV in radians
residence time of measurement for across-track scanner (whiskbroom)
dwell time
relationship between signal coming from the target to extraneous/background electronic noise in across-track scanner (whiskbroom)
signal to noise ratio
ground resolution element or ground resolution D
spatial resolution
the ability to discriminate very slight energy differences
radiometric resolution
ability to discriminate fine spectral differences
spectral resolution