Overlapped sub-aperture algorithm applicable to missile-borne high forward-squint time-varying parameter SAR

Abstract

The invention discloses an overlapped sub-aperture algorithm applicable to a missile-borne high forward-squint time-varying parameter SAR (Synthetic Aperture Radar). The algorithm mainly comprises thefollowing seven steps: 1, performing two-dimensional dechirping; 2, performing residual video phase correction; 3, performing wave number domain data format correction; 4, performing azimuth sub-aperture data segmentation; 5, performing azimuth coarse data focusing; 6, performing azimuth fine data focusing; 7, performing sub-aperture data splicing. According to the overlapped sub-aperture algorithm provided by the invention, the assumed error phase of a wave front plane of the sub-aperture data is limited by utilizing the sub-aperture data, a space-varying quadratic error phase is compensatedby utilizing the coarse focusing result of the sub-aperture data, and the overlapped sub-aperture algorithm is a high-efficiency and accurate imaging processing method.

Description

technical field [0001] The present invention relates to the technical field of synthetic aperture radar (Synthetic Aperture Radar, referred to as SAR), in particular, refers to an overlapping sub-aperture imaging processing method suitable for the time-varying parameter SAR of the missile-borne large forward squint. Background technique [0002] Missile-borne SAR is an all-weather and all-time microwave imaging tool, which is suitable for earth observation under complex meteorological conditions. The polar coordinate format algorithm is an imaging processing algorithm suitable for spotlight mode. It utilizes the time-frequency equivalence of the dewired FM signal to correct the range migration in the frequency domain with a two-dimensional interpolation method. Although the traditional polar coordinate format algorithm theoretically has the ability to focus on the echo signal of the missile-borne SAR in the forward squint configuration, due to the strong space-varying charac...

AI Technical Summary

Problems solved by technology

Although the traditional polar coordinate format algorithm theoretically has the ability to focus on the echo signal of the missile-borne SAR in the forward squint configuration, due to the strong space-varying characteristics of the signal in the wavenumber domain, it can be used to calculate the range wavenumber for range interpolation correction. The common area is greatly compressed, resulting in a sharp deterioration of the distance resolution. In the extreme case, if the common area of ​​the distance wavenumber does not exist, imaging processing cannot be performed.

Images