Corner reflectors' responses observed by X-band polarimetric airborne synthetic aperture radar

In order to make radiometric calibration of an X-band airborne synthetic aperture radar (SAR), calibration targets of trihedral corner reflectors (consisting of four different sizes) were imaged several times. The radar was developed by the Communications Research Laboratory (CRL) for research purposes and has been operated, with polarimetric and interferometric functions, simultaneously with an L-band SAR developed by the National Space Development Agency of Japan (NASDA). The authors show some results of the calibration experiments with the reflectors deployed in a dune in 1998 focusing on radiometric calibration of like-polarization (HH and VV) images. Also shown are results of a similar calibration experiment in a frozen lake in 1999, to verify calibration coefficients estimated from the previous experiment.