SAR Image Simulation Method for Metal Ball Target

Abstract

The invention provides a SAR image simulation method for a metal ball target. The method includes the steps of calculating a metal ball SAR echo signal according to a SAR imaging geometry and a scattering theory, ignoring variation of the scattering intensity of a metal ball with frequency; and obtaining a simulated SAR image according to the SAR imaging principle and the metal ball SAR echo signal. According to the scattering analytic formula and scattering mechanism of the metal ball target, the variation of the scattering intensity with frequency is ignored, the influence of the variation in the distance history during the interaction with a SAR on image characteristics is emphatically calculated, the variation in the image characteristics caused by the variation in the distance history of a scattering center of the metal ball target in an azimuth direction can be effectively simulated, so that the simulated image can characterize the main characteristics of the metal ball SAR image, and the shortcomings of failure to obtain scattering characteristics of the metal ball, large calculation amount and slow simulation speed of an existing simulation method are overcome.

Description

technical field [0001] The invention belongs to the field of synthetic aperture radar imaging and scattering mechanism, and relates to a SAR image simulation method for a metal ball target. Background technique [0002] In recent years, the field of remote sensing has developed rapidly, and high-resolution spaceborne and airborne synthetic aperture radar (SAR) imaging systems have emerged continuously. SAR has become one of the important means of earth observation. In order to effectively use SAR images, the SAR image Research on understanding and simulation problems has become a hot spot. SAR image simulation is a means of simulating and predicting target features based on the scattering mechanism of SAR images, and it has also become one of the key technologies for subsequent recognition applications. Therefore, understand the scattering mechanism of SAR images and accurately obtain target parameters from SAR images. , and then establishing the relationship between SAR im...

AI Technical Summary

Problems solved by technology

[0003] The traditional SAR image simulation method uses the method of calculating the two-dimensional frequency domain scattering coefficient, which needs to calculate the two-dimensional scattering of the target according to the SAR imaging geometry and observation conditions. This simulation process basically conforms to the formation process of the SAR echo, and can effectively achieve the target simulation, but the above method is applicable to all targets but not targeted, the amount of calculation is huge, and the simulation speed is slow; in the follow-up research, many methods to improve the simulation speed have been developed, most of which are based on the idea of ​​projection. The scattering does not change with the angle and frequency, and the scattering of the target at the center of the SAR beam is replaced by the scattering of the entire synthetic aperture time, thereby simplifying the simulation process; however, for the metal ball target, the above method still has the following technical problems:

[0004] Both the traditional simulation method and the method based on projection thought uniformly discretize the target surface into surface elements of uniform magnitude. For the metal ball target, there is a lot of calculation redundancy in the scattering calculation, and the simulation speed is slow; the metal ball target surface Smooth, corresponding to the sliding scattering center structure, the simulation method based on the projection idea cannot reflect the influence of the SAR image imaging process on the image characteristics, and the calculation error will randomly generate false scattering centers on the image, resulting in large errors in simulation results

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