Calibration method for onboard hybrid along-track and cross-track interference synthetic aperture radar system

Abstract

The invention provides a calibration method for an onboard hybrid along-track and cross-track interference synthetic aperture radar (SAR) system. According to the method, a new baseline vector model is established for an onboard hybrid along-track and cross-track interference synthetic aperture radar. According to the model and the attitude angle information of an aerial carrier, the baseline vector of the hybrid interference SAR system at any time can be described. On the basis of the new baseline vector model, the to-be-calibrated parameters of the hybrid interference SAR system are modified, and then the calibration method applicable to the onboard hybrid along-track and cross-track interference synthetic aperture radar is provided. Based on the method, the calibration for the baseline length and two baseline angles is realized through calibrating the baseline component at a certain moment. Therefore, the complex formula calculation is avoided, and the method is more easily implemented.

Description

technical field [0001] The invention belongs to the technical field of synthetic aperture radar (Synthetic Aperture Radar, SAR), in particular to an airborne hybrid along-track-cross-track interference synthetic aperture radar calibration method. Background technique [0002] Synthetic aperture radar is an advanced active microwave earth observation method, which has been widely used because of its all-time, all-weather, high-resolution and certain penetration of ground vegetation. Interferometric Synthetic Aperture Radar (Interferometric Synthetic Aperture Radar, Interferometric SAR or InSAR) is a combination of radio interferometry technology and synthetic aperture radar technology. deformation and other information. The relative position between the two antenna phase centers in the interferometric SAR system is called the interferometric baseline. According to the baseline type, the interferometric SAR can be divided into two antenna phase centers placed along the track ...

AI Technical Summary

Problems solved by technology

[0005] First, the baseline vector model is not sufficient for the AT-XT InSAR system. Specifically, the hybrid AT-XT InSAR system has both the along-track baseline component and the cross-track baseline component. Compared with the pure ATI-SAR or XTI -SAR system, its baseline vector model is more complex, the above baseline vector model cannot comprehensively and correctly describe the baseline characteristics of the AT-XT InSAR system, so the baseline needs to be remodeled for the hybrid AT-XT InSAR system

[0006] Second, as above, since the above baseline vector model is not applicable to the airborne AT-XT InSAR system, the above parameters to be calibrated cannot cover all the parameters to be calibrated in the AT-XT InSAR system, and the parameters to be calibrated need to be modified accordingly

[0007] Third, the calibration method is only for the calibration of the XTI-SAR system, which is only a special case when the baseline of the AT-XT InSAR system is zero. It is necessary to study the calibration method suitable for the hybrid AT-XT InSAR system

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