Multi-polarization SAR compact polarimetry calibration method

Abstract

The invention provides a multi-polarization SAR compact polarimetry calibration method which comprises a calibration field compact polarimetry SAR data preprocessing process and a polarization distortion parameter calibration process. In the calibration field compact polarimetry SAR data preprocessing process, compact polarimetry SAR data radiation correction and Faraday rotation correction are mainly completed. In the polarization distortion parameter calibration process, four different types of common corner reflectors are used as reference calibrators, and a compact polarimetry calibration method (namely, a compact polarimetry polarization distortion parameter calibration method) is deduced based on a calibration model. Through the method, a polarization distortion parameter can be calibrated precisely. The calibration algorithm does not depend on the absolute RCS values of the corner reflectors, and calibration error caused by RCS inconsistency of different corner reflectors can be avoided effectively. The algorithm is of high robustness and practicability.

Description

technical field [0001] The invention relates to a multi-polarization SAR simplified polarization mode calibration method, which belongs to the technical field of synthetic aperture radar (SAR) data processing. Background technique [0002] Spaceborne Synthetic Aperture Radar (SAR), as an important means of high-resolution microwave remote sensing for earth observation, has received more and more attention in recent years. SAR has all-day and all-weather working capabilities, and can obtain high-resolution images of targets in multi-band and multi-polarization modes, so it is widely used in terrain mapping, ocean monitoring, disaster reduction and prevention, agriculture, forestry, and military reconnaissance. play an important role. [0003] Compact Polarimetry is an important working mode of multi-polarization SAR, which uses the dual-polarization SAR system to construct the pseudo-full polarization information of the observation target. The simplified polarization mode t...

AI Technical Summary

Problems solved by technology

[0007] The technical problem of the present invention is to overcome the deficiencies of the existing reduced polarization mode calibration method and provide an improved multi-polarization SAR reduced polarization mode calibration method. This method only uses corner reflectors to complete the reduction The calibration of the polarization distortion parameters in the polarization mode requires simple equipment; the calibration algorithm uses the relative ratio of the different polarization channel components of the corner reflector to solve the polarization distortion parameter error, and does not need to know the exact value of each corner reflector Absolute amplitude and phase values, and there is no requirement for the consistency of absolute amplitude and phase values ​​​​of different corner reflectors, so the requirements for machining accuracy of diagonal reflectors are relatively low, and the practicability is stronger

Images