MAC Europe 1991 Campaign: Design and Performance of an Active Radar Calibrator

This paper describes the characteristics and performance of an Active Radar Calibrator (ARC) used during the MAC Europe 1991 Campaign conducted in Southern Italy (Matera) to calibrate the Airborne Synthetic Aperture Radar (AIRSAR) and Topographic Synthetic Aperture Radar (TOPSAR) instruments which were flown onboard the NASA/JPL-DC8 aircraft. The main design considerations and the ARC hardware performance are presented. The laboratory measured values of radar cross section and propagation delay time are compared to those obtained from the images acquired during the flight. The TOPSAR raw data have been compressed with a Range-Doppler processor which includes range migration correction. The radiometric calibration, performed with the intensity integration method, gave a backscattenng coefficient accuracy of +0 X dB Hie ARCs' radar cross-sections extracted from the calibrated images have been compared with the laboratory experimental data, giving results in good agreement widi the anechoic chamber tests. The laboratory tests gave an absolute calibration error of +0.6 dB.