Building Earth Observation Cameras

205Pushbroom Imagers

6.11 Hybrid Scanner

Both whiskbroom and pushbroom imaging systems, on a low Earth orbiting

satellite, generates images in one direction (AT) due to spacecraft motion.

We have seen in Chapter 5 that from a geostationary orbit (GEO) the cam-

era system has to produce scanning in two directions (E-W & N-S) to form

the image. It is possible to incorporate a linear CCD in one direction and

mechanical scanning in the other direction to form a two-dimensional image

from a GEO. That is a hybrid of optomechanical scanning and pushbroom

scanning.

Although imaging from GEO was started for meteorological applica-

tions, there were NAS