Ww. Gregg et Fs. Patt, ASSESSMENT OF TILT CAPABILITY FOR SPACEBORNE GLOBAL OCEAN COLOR SENSORS, IEEE transactions on geoscience and remote sensing, 32(4), 1994, pp. 866-877
The importance of tilt capability for sun glint avoidance for future g
lobal ocean color missions was analyzed. The analyses focused on Sea-v
iewing Wide Field-of-view Sensor (SeaWiFS) mission, because its radiom
etric, orbital, and sensor characteristics are well defined. The analy
ses concentrated on two major questions: 1) does tilting to avoid sun
glint increase or decrease the total ocean coverage, and 2) at high la
titudes far from the region of maximum sun glint, should the sensor be
tilted or untilted? For ocean coverage maximization, if the sensitivi
ty of ocean color algorithms to sun glint is of the same order as the
error in the atmospheric correction algorithms, then a tilted sensor p
roduces nearly 20 percent better coverage than an untilted one after 2
d in the absence of clouds, and 12 percent after 4 d including clouds
. Thus, the tilt capability can improve the ocean coverage of future o
cean color missions. At high latitudes differences in transmitted wate
r-leaving radiance between tilted and untilted sensors were well withi
n the algorithm errors. Furthermore, sun glint radiances exceeding the
algorithm errors occurred at high wind speeds as far as 70-algorithms
from the solar declination, suggesting that sensors should remain in
the tilted mode up to this limit.