Calibration method for polarization synthetic-aperture radar

Abstract

The invention belongs to the field of radar communication technology and discloses a calibration method for a polarization synthetic-aperture radar. The method comprises the steps of acquiring the echoed data of the fully polarimetric scattering process; establishing a polarization calibration model for the polarization synthetic-aperture radar; calculating the unbalanced parameters of a cross polarization channel in the polarization calibration model and the crosstalk parameters of a polarization channel; according to the unbalanced parameters of the cross polarization channel and the crosstalk parameters of the polarization channel, preliminarily correcting the echoed data of the fully polarimetric scattering process to obtain preliminarily corrected echoed data; calculating the unbalanced parameters of a receiving channel, correcting the preliminarily corrected echoed data for a second time according to the unbalanced parameters of the receiving channel, and finally obtaining the calibration data of the full-polarization synthetic-aperture radar. According to the method, the parameter estimation performance is still ensured to be excellent on the premise that the noise powers of cross channels are not consistent and the signal to noise ratio is low.

Description

technical field [0001] The invention relates to the technical field of radar communication, in particular to a calibration method for polarization synthetic aperture radar. Background technique [0002] Polarization SAR remote sensing has been extensively researched and applied in ground object classification, surface roughness and soil moisture estimation, and agricultural applications. In recent years, numerous airborne and spaceborne polarimetric SAR systems have been successfully developed at home and abroad. At present, the airborne polarization systems that are still performing flight tests mainly include the German F-SAR system, the American UAVSAR system and the Japanese PiSAR-2 system; the spaceborne polarization systems mainly include the German TanDEM-X system and the Japanese ALOS-2 system system etc. Using these systems, a large amount of polarization data has been obtained at home and abroad. In practical applications, all polarization analysis and applicati...

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Problems solved by technology

[0005] However, in practical applications, we found that the Ainsworth algorithm did not consider the influence of cross-polarization channel noise in the process of estimating the unbalanced parameters. Therefore, when the cross-polarization channel noise cannot be ignored, the parameter estimation accuracy will decrease, resulting in extreme The distortion of the normalized data cannot be corrected correctly

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