| dc.description.abstract | This paper developed an Active Radar Calibrator to calibrate the C-band SAR imaging radar system, we carried out the design process of the Active Radar Calibrator (ARC) and calibration experiment of the C-band synthetic aperature radar (SAR) of both ERS-2 and ENVISAT. On I March 2002, the European Space Agency launched ENVISAT, an advanced polar-orbiting Earth observation satellite which will provide measurements of the atmosphere, ocean, land, and ice over a five year period. The ENVISAT satellite has an ambitious and innovative payload that will ensure the continuity of the data measurements of the ESA ERS satellite. The ARC is designed return both V and H radar signals with two transmission antennas and it was identified clearly including a 4 s delay and system gain(RCS=75.97dBm2) for radiometric calibration. For calibration of the C-band SAR, we have employed an ARC located in grassland near the Jhong-Ping elementary school in Chung-Li, Taiwan. We estimate the accurate azimuth and elevation angles in order to acquire the calibration constant (K) from the image data, we have examined image amplitude (date numbers) and locations of the ARC. It is seen in the SAR image, as expected, that the positions of the ARC delay points are shifted depending on the delay time.This paper describes (1) The ARC design process and laboratory measurement performed to characterize the hardware performance, with measurement of component and propagation delay. (2) the method and preliminary results of the calibration constant (K) from the image date. | en_US |