Building Earth Observation Cameras

276 Building Earth Observation Cameras

slit that denes the swath and IFOV, providing a 7.5-km swath and 30-m spatial

resolution from the orbit altitude of 705 km. The imaging telescope is an off-

axis TMA with an aperture of 12.5 cm. A dichroic beam splitter behind the slit

reects 400–1000 nm to the VNIR spectrometer and transmits 900–2500 nm

to the SWIR spectrometer. Both spectrometers use a JPL convex grating design

in a three-reector Offner conguration and provide a spectral resolution of 10

nm. The two grating imaging spectrometers relay the slit image to two focal

planes at a magnication of 1.38:1 (Lee et al. 2001). The focal plane dimension

parallel to the slit axis provides the cross-track spatial image, whereas the axis

perpendicu ...