Maneuvering trajectory synthetic aperture radar self-focusing imaging method and device and radar system

Abstract

The invention relates to a maneuvering trajectory synthetic aperture radar self-focusing imaging method. The method comprises the steps: echo data of a synthetic aperture radar are acquired; BP sub-images of the data at each azimuth moment are obtained; the phase error of each azimuth moment is estimated to obtain a phase error vector; the estimated phase error vector is unwrapped; the data envelope offset of each azimuth moment is calculated according to the unwrapped phase error vector and the emission signal wavelength of the synthetic aperture radar, and the distance vector is transferredaccording to the envelope offset to obtain echo data after envelope compensation; then the echo data subjected to distance compression is replaced with the echo data subjected to envelope compensationto obtain a sub-image at each azimuth moment; all the steps are repeated to obtain a phase error at each azimuth moment; and performing compensation on corresponding phase errors for the sub-images to obtain the full-aperture SAR image. According to the method, the envelope offset and the phase error are compensated at the same time, and the influence of the motion error on SAR imaging can be eliminated more accurately.

Description

technical field [0001] The application belongs to the technical field of radar imaging, and in particular relates to a maneuvering trajectory synthetic aperture radar self-focusing imaging method, device and radar system. Background technique [0002] Synthetic Aperture Radar (SAR) is an active active microwave remote sensing imaging radar, which obtains an equivalent large-aperture antenna through the movement of the antenna, obtains high-resolution radar azimuth, and obtains high-resolution range through pulse compression technology. rate, and finally obtain a two-dimensional high-resolution radar image of the observed scene. The motion trajectory of the antenna phase center (APC) needs to be used in SAR imaging processing. Due to factors such as measurement equipment accuracy and airflow disturbance, there is an error in the measurement value of the APC trajectory, which is called motion error, which will cause defocusing and distortion in the SAR image. Reduce image qua...

AI Technical Summary

Problems solved by technology

However, the existing motion error compensation methods only perform phase compensation and ignore the envelope offset, which will lead to inaccurate motion compensation and unsatisfactory SAR image focusing effect

This is a major drawback of existing motion compensation methods

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