Method for generating three-dimensional imaging original echoed signals of chromatography synthetic aperture radars

Abstract

The invention relates to a method for generating three-dimensional imaging original echoed signals of chromatography synthetic aperture radars, which comprises the following steps: taking a three-dimensional image containing backward plural scattering coefficients of imaging area targets in a rectangular coordinate system OXYZ as the input, carrying out three dimensional fourier transform on the three-dimensional image and converting an image signal to a rectangular coordinate system wave-number domain; converting signals in Kx, Ky and Kz domains to be signals in Kw, Ku and Kv domains according to the method of converting the rectangular coordinate system to a spherical coordinate system; introducing imaging geometrical relationships among same imaging area of chromatography synthetic aperture radars by multiplying three dimensional filter function H2 (Kw, Ku and Kv); introducing a transmission signal form by the multiplication of a two-dimensional inverse Fourier transform function and a reference phase function; and at last, by W direction process and other operations, obtaining the three-dimensional imaging original echoed signals of chromatography synthetic aperture radars, which contains a carrier frequency. The method can be used for generating three-dimensional imaging original echoed signals of side-looking, downward-looking, forward-looking, backward-looking and downward side-looking chromatography synthetic aperture radars, and has high echo generating efficiency and easy realization of modularization.

Description

technical field [0001] The invention relates to the technical field of information acquisition and processing, in particular to a method for generating original echo signals of tomographic synthetic aperture radar three-dimensional imaging. Background technique [0002] Tomosynthetic aperture radar imaging technology is a new type of synthetic aperture radar three-dimensional imaging technology, which was proposed by A. Reigber and A. Moreira et al. at the end of the 20th century (A. Reigber and A. Moreira. -band data", Processing of IGARSS 1999, Hamburg, Germany, 1:44-46). Such as figure 1 As shown, the tomosynthetic aperture radar sensor emits a signal with a certain bandwidth, and the movement of the platform where the tomosynthetic aperture radar sensor is located moves in the Y direction to form the first synthetic aperture; The same imaging area is observed from multiple perspectives along the Z direction, and a second synthetic aperture different from the Y-directio...

AI Technical Summary

Problems solved by technology

It can be seen from formula (1) that for each point target P n (x n ,y n ,z n ), tomosynthetic aperture radar needs to calculate each target P n (x n ,y n ,z n ) to the distance between the tomosynthetic aperture radar, and then generate the echo signal and communicate with the target P n (x n ,y n ,z n ) of the scattering coefficient σ n Multiplied together, it is assumed that the tomosynthetic aperture radar flies along the OYZ to form about the point target P n (x n ,y n ,z n ) of the two-dimensional synthetic aperture plane along the Y direction and the number of points in the Z direction are n y and n z , it is necessary to repeat the above process for each point target in the imaging area. Therefore, this method is only suitable for echo generation of a small number of point targets. For complex targets or a large number of observation targets or scenes in a large space, due to the The number of point targets is too large, the echo generation is extremely time-consuming, and it is also not conducive to the modularization of hardware devices such as computers

[0010] In 2007, Meng Xiangxin, Xue Minghua and Wang Zhenrong carried out the research on the generation method of point target echo signal (data) related to inverse synthetic aperture radar 3D imaging (Meng Xiangxin, Xue Minghua, Wang Zhenrong, "Microwave 3D imaging discrete point target echo data simulation", Electronic Measurement Technology, Vol. 30, No. 8, August 2007), in the generation method of the inverse synthetic aperture radar three-dimensional imaging echo signal, it is assumed that the transmitted signal is "a plane wave emitted by a compact field", and "the target is around the Rotate a fixed point", regardless of "the influence of the distance between the inverse synthetic aperture radar and the center of the observed target on the echo generation", the essence of the echo generation process is still based on the "vector superposition of reflected waves", that is, the use of time domain The generation method of coherent superposition needs to calculate the "azimuth and elevation angle" of each point target relative to the inverse synthetic aperture radar. As the number of point targets increases or the amount of inverse synthetic aperture radar data collection increases, its echo The amount of calculation in the generation process increases linearly with the increase of the number of point targets. For complex targets or a large number of observation targets or scenes in a large space range, the echo generation process will be more time-consuming due to the large number of point targets involved. ; This method is only suitable for the generation of inverse synthetic aperture radar three-dimensional imaging echo signals of a small number of point targets in a small range. The generated inverse synthetic aperture radar three-dimensional imaging echo signal introduces a large error

This method is not suitable for tomosynthetic aperture radar three-dimensional imaging echo signals of complex targets or a large number of observation targets or scenes in a large space range

[0011] At present, there is no in-depth research on the original echo signal generation method of tomosynthetic aperture radar 3D imaging in China, and there are no literatures or patents related to the echo generation method of tomosynthetic aperture radar

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