Two dimentional attitude control system of synthetic aperture radar satellite

Abstract

The invention discloses a two dimentional attitude control system of a synthetic aperture radar satellite, which includes a satellite position analysis module, a satellite position analysis module and an expected attitude determination module. The two dimentional attitude control system is applied in the situation that the synthetic aperture radar satellite runs on an elliptic orbit, and echoed signal doppler center frequency can be controlled to be zero by applying yaw-pitch-two-dimensional attitude control technology, thus effectively weakening the degree of coupling between distance vector and direction vector and lowering the difficulty and operand of imaging process.

Description

technical field [0001] The invention relates to a control system for radar satellite attitude. More specifically, it refers to a two-dimensional attitude control system for synthetic aperture radar satellites. Background technique [0002] The synthetic aperture radar satellite is installed on a moving platform, transmits and receives pulses according to a certain repetition frequency, and coherently superimposes the target echo signals received within a period of time, so as to obtain the detection effect of the large-aperture antenna array and achieve high azimuth resolution , while using pulse compression technology to achieve high range resolution. [0003] Compared with the real aperture radar satellite, the biggest feature of the synthetic aperture radar satellite is that it uses the relative motion between the radar and the target to generate the Doppler frequency shift effect, forms the azimuth spectrum, and improves the azimuth resolution through matched filtering....

AI Technical Summary

Problems solved by technology

[0005] 1. The increase of the range migration makes the response of the point target diffuse in the range direction, and the range-wise matched filter needs to consider the cubic term of the range spectrum, perform secondary distance compression or use a more accurate imaging processing algorithm, which increases the calculation amount of the algorithm and The difficulty of imaging processing reduces the efficiency of data processing;

[0006] 2. The degree of geometric distortion of the image increases, and more complex correction techniques must be adopted to ensure the relative position accuracy and absolute position accuracy of the radar image, which increases the burden of image post-processing;

[0007] 3. It is difficult to obtain sufficient Doppler spectrum overlap during the interference of spaceborne synthetic aperture radar satellites, which reduces the accuracy of interference;

[0008] 4. The rotation speed of the earth has not been completely canceled out. In the process of multi-channel ground slow-moving target detection, it is difficult to improve the level of clutter suppression.

However, this technology does not take into account the situation that the satellite is running in an elliptical orbit, and can only achieve the best results under the condition of a circular orbit

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