Contour-enhanced beaming-type synthetic aperture radar imaging method

Abstract

The invention discloses a contour-enhanced beaming-type synthetic aperture radar imaging method, which mainly solves the problems that the traditional SAR (synthetic aperture radar) imaging algorithm has stronger dependency on scene echo data received in an azimuth direction and a formed image is blurred in contour and low in resolution rate. The contour-enhanced beaming-type synthetic aperture radar imaging method comprises the following implementing steps of: establishing a beaming SAR distance contour imaging model by using a tomography modeling method, sequencing all azimuth dimensions of data according to a receiving sequence and continuously projecting the sequenced data to an image domain of a scene to be imaged to obtain a primary imaging result; and projecting a primarily formed image to a sparse transform domain for representing the image contour, and carrying out alternate iteration solution on a target function by virtue of an alternate iteration idea to finally obtain the contour-enhanced SAR image. The contour-enhanced beaming-type synthetic aperture radar imaging method disclosed by the invention has the advantages of greatly reducing azimuth-dimensional echo data required by imaging, overcoming the influence of side lobes of a point spread function on the imaging resolution ration and carrying out high-resolution imaging on an airborne radar under the condition that the azimuth-dimensional echo data is insufficient.

Description

Technical field [0001] The present invention belongs to the technical field of microwave radar, and relates to area target imaging. Furthermore, it is a contour-enhanced spotlight synthetic aperture radar SAR imaging method, which can be used for airborne radars to perform high-altitude under the condition of insufficient azimuth-dimensional echo data. Resolution imaging. Background technique [0002] With the rapid development in the fields of earth surveying and mapping, military reconnaissance and target recognition, higher and higher requirements are put forward for image resolution. The spotlight synthetic aperture radar has a large imaging angle of view, that is, it can stare at the target scene and obtain more target information, so it can obtain high-resolution microwave remote sensing images in the imaging area. Among them, in order to make the obtained images more conducive to the application of technologies such as target recognition and image segmentation, contour en...

AI Technical Summary

Problems solved by technology

In practice, the distance resolution is usually improved by increasing the bandwidth of the transmitted signal, which puts forward higher requirements on the performance of the analog-digital sampling system; at the same time, the improvement of the azimuth resolution is mostly by increasing the coherent accumulation time of the echo. That is to increase the number of observations in the azimuth dimension, which undoubtedly increases the burden of storage and transmission, and makes this technology impossible for real-time imaging in some special applications

[0004] Traditionally, SAR imaging of targets with obvious contour features in the scene mainly uses imaging algorithms based on FFT and interpolation operations, such as polar coordinate format algorithm, distance migration algorithm and Chirp Scaling algorithm, etc., but the common disadvantage of these methods is that the logarithmic The accuracy of mode sampling is high, and the scene echo data received in azimuth is highly dependent, and because the side lobes of the point spread function will cause the outline of the target image to be blurred, it is difficult to improve the imaging resolution

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