Optimization method for azimuth ambiguity in space-borne TOPSAR mode

Abstract

The invention discloses an optimization method for azimuth ambiguity in a space-borne TOPSAR mode, which comprises the following steps: reading in relevant parameters; acquiring azimuth beam 3dB width, the shortest slant distance from a satellite to a target, a mixed factor, the shortest slant distance from the satellite to an equivalent rotation point, the maximum angle of center beam scanning, separation of azimuth antenna array elements, coordinates of a selected position of the azimuth, and the azimuth ambiguity of a selected position of the azimuth; drawing a changing curve of the azimuth ambiguity; and acquiring the worst value of the azimuth ambiguity under different pulse recurrence frequencies and drawing the worst value curve of the azimuth ambiguity. In the invention, when the azimuth ambiguity is acquired, the space-variant characteristic with the azimuth is considered fully, and the result has higher reliability; the azimuth ambiguities in different positions are acquired independently and can be parallel processed to improve the processing efficiency; and the changing curve of the azimuth ambiguities with the azimuth positions visually reflects the changing condition of the azimuth ambiguities in the whole azimuth scene.

Description

technical field [0001] The invention belongs to the field of signal processing, and relates to an optimization method, in particular to an optimization method for azimuth ambiguity in a spaceborne TOPSAR mode. Background technique [0002] Synthetic Aperture Radar (SAR) is an active ground-imaging microwave radar. Compared with ordinary optical imaging radar, it is not affected by weather and climate, and can complete the earth observation mission all-weather and all-weather. Therefore, it has been widely used in military reconnaissance, resource detection, ocean observation, ecological monitoring and so on. [0003] The azimuth ambiguity is an important index in spaceborne SAR, which directly reflects the degree of interference of the azimuth sidelobe signal to the main lobe signal. In system design and wave position selection, azimuth ambiguity is one of the main assessment indicators. one. In imaging processing, we aim at the echo signal in the main lobe (beam width cor...

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Problems solved by technology

[0005] The purpose of the present invention is to solve the problem that the azimuth ambiguity and the scanning angle change with the azimuth position are not considered in the current spaceborne TOPSAR working mode, and at the same time, the optimization of the azimuth ambiguity is not realized by setting the pulse repetition frequency , propose an optimization method for azimuth ambiguity in spaceborne TOPSAR mode

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