Cross-calibration experiment of airborne L-band polarimetric SAR

Cross-calibration experiment of airborne L-band SAR systems, the JPL´s AIRSAR and the NASDA/CRL´s PI-SAR, was conducted on the Tottori sand dune. This experiment forms a part of PacificRim-2 campaign from July to October in 2000. Both AIRSAR and PI-SAR acquired the data over the test site within two hours on October 4, 2000. The track altitudes of airplanes were about 8000 m. Four rectangle trihedral corner reflectors with 80 cm of leg-length were deployed in order to derive absolute calibration coefficients. We also deployed four dihedral corner reflectors with different rotation angles for polarimetric calibration purpose. This report describes the results of calibration experiment for JPL´s AIRSAR and NASDA/CRL´s PI-SAR conducted on Tottori sand dune. Since the AIRSAR data has not been available yet, this report concentrates on the calibration of our PI-SAR system. The distortion matrices for both transmitting and receiving system can be calculated by using the data containing one trihedral reflector and two dihedral reflectors with different rotation angles. Gain balance between HH and VV was not good in this time, because the PI-SAR had some hardware degradation. The absolute calibration coefficient for HH channel has the almost same value as the previous calibration experiment in 1999. However, we found that the VV channel had been degraded more than 3 dB. The improvements of gain balance and cross-talk between H and V channels were confirmed after the calibration using the extracted distortion matrices