What are the main differences between ATSR-1, ATSR-2 and AATSR?
ATSR-1 measured in the infra-red at 1.6 m, 3.7 m, 11 m and 12.0 m and had no visible channels. ATSR-2 and AATSR include the same four infra-red channels of ATSR-1 and three additional channels at 0.55 m, 0.67 m and 0.87 m. The ATSR-2 instrument is largely the same as ATSR-1, differing only in the inclusion of the extra channels and an on-board visible calibration system. AATSR is functionally largely similar to ATSR-2, but components have been redesigned to match the new platform environment of ENVISAT. The details of the scan, calibration systems, spatial resolution and swath have been kept as close as possible to the earlier instruments to ensure data continuity. The major advantage of AATSR over ATSR-2 is in the downlinking of data. ATSR-2 had restrictions on the amount of data that could be downlinked, due to platform constraints, which particularly affected the visible channels, whereas AATSR can send down data from all the channels continuously at full 12-bit radiometric resoluti
