Mixing degree extracting method for Missile-borne non-ideal staring spotlight SAR (synthetic aperture radar)

Abstract

The invention discloses a mixing degree extracting method for a missile-borne non-ideal staring spotlight SAR(synthetic aperture radar). The method comprises the following steps of: computing a vertical distance h between a underground wave beam centre intersection distance and a ground distance through a given initial height H0 and initial mixing degree M0; determining an ideal staring point formed in the wave beam centre according to a known starting point, incident angle and squint angle; determining a trace point position corresponding to a staring point by combining the incident angle and the squint angle according to a known non-ideal staring coordinate, directional speed and time the non-ideal staring point appears; computing the mixing degree according to the obtained trace point height; and respectively mapping the ground non-ideal staring points onto a missile movement trace according to the obtained result, and respectively computing the corresponding mixing degree so as tofit the corresponding time-varying mixing degree expression M(t)=f(t). The mixing degree extracting method can be effectively applied to various complex missile traces, simplifies the simulation process, and lays a foundation for subsequent system performance analysis and imaging quality analysis and compensation.

Description

technical field [0001] The invention relates to a method for extracting a mixture degree of a missile-borne non-ideal staring spotlight synthetic aperture radar (SAR), which belongs to the technical field of signal processing. Background technique [0002] The emergence of the concept of synthetic aperture radar can be traced back to 1951. Carl Wiley of Goodyear Aerospace in the United States discovered that the vertical resolution of the beam can be improved by processing the Doppler frequency shift. Based on this, the radar can be used to obtain a two-dimensional surface image. The idea of ​​constructing an equivalently long antenna through signal analysis technology is called Synthetic Aperture Radar (SAR). [0003] The emergence of synthetic aperture radar has expanded the original radar concept, so that it has the ability to image and identify targets (aircraft, missiles, ground, etc.), and has shown great potential in the application of microwave remote sensing. Nati...

AI Technical Summary

Problems solved by technology

First of all, the degree of mixing will affect the coherent accumulation time of each point in the azimuth direction, thereby affecting the azimuth resolution. After derivation, the theoretical value of the azimuth resolution in the mixed mode is (D is the azimuth aperture of the antenna, and M is the degree of mixing); secondly, the degree of mixing will affect the width of the azimuth mapping band; in addition, the degree of mixing will also make the main lobe of the echo signal broaden, the side lobe is depressed, and the azimuth resolution is relatively focused The mode has declined, which in turn affects the image quality

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