Calibration of Dual Polarimetric C-Band SAR Data: A Possible Approach for SENTINEL-1
Abstract
In this paper we discuss the radiometric calibration of dual polarimetric Synthetic Aperture Radar (SAR) data. The polarimetric distortion model of a dualpol SAR includes four calibration complex parameters: the cross-talk on transmit, the receiving channel imbalance and two receiving cross-talks. While these parameters can be estimated in a full-pol system using distributed targets with reflection symmetry, we show that the absolute and polarimetric calibration of a dual-pol acquisition mode can be carried out using a trihedral-like and an oriented dihedral-like response inside the SAR scene, plus a distributed target having azimuthal symmetry. An alternative approach might use two gridded trihedrons in place of the distributed target and the dihedron. For both approaches we derive the expression of the distortion parameters and assess the performance using the system characteristics of Sentinel-1. The reciprocity assumption between transmit and receive is not needed. We conclude that gridded trihedrons are more appropriate for the dualpol calibration since they have low polarimetric noise compared with the calibration requirements.
- Publication:
-
Science and Applications of SAR Polarimetry and Polarimetric Interferometry PoIInSAR 2009
- Pub Date:
- April 2009
- Bibcode:
- 2009ESASP.668E...9L