11/02/04 18:04:37
>>895
TDI （Time Delay Integration） を使っている衛星，ざっと調べたところ
IKONOS
Quickbird
WorldView-1
WorldView-2
EROS B
AlSat-2 (Algeria Satellite-2)
URLﾘﾝｸ(www.gisdevelopment.net)
The satellite moves some 7 km/s, what means that the ground pixel 1 m
for a single element CCD is exposed within the time of 0.14 ms.
This time is too short; for creation of sufficient charge on CCD elements,
one needs at least min. 0.7 ms, what corresponds to the distance of 5 m.
In order to solve this problem, one uses so called TDI - Time Delay Integration.
Every panchromatic line of CCD contains a dozen or more physical lines,
thus forming a rectangular table CCD of shape enhanced orthogonally
to the direction of flight.