Data-takes on two ascending orbits of the Shuttle Imaging Radar-B (SIR-B) over an agricultural test site in west-central Illinois were used to establish end-to-end transfer functions for conversion of an 8-bit image digital number to the radar backscattering coefficient. The transfer function for each data-take was defined by radar response to an array of six calibrated transponders and to area-extended targets measured by externally calibrated, truck-mounted scatterometers. The radar cross section of each transponder was measured on an antenna range. The truck-mounted scatterometers observed 20 to 80 fields daily at L-band with HH polarization and at azimuth viewing angles and incidence angles equivalent to those of the SIR-B. For each pass, the SIR-B's thermal noise was estimated from surfaces expected to yield specular reflection.
External calibration of SIR-B imagery with area-extended and point targets
Externe Kalibrierung von SIR-B Darstellungen mit Gelaende- und punktfoermigen Zielen
1985
2 Seiten
Conference paper
English
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