Two-dimensional ISRA imaging method of object with micro rotation in air

Abstract

The invention discloses a two-dimensional ISRA imaging method of an object with micro rotation in the air. The method comprises the following steps that: (1), a radar matriculates an ISAR echo; (2), translation compensation is carried out; (3), time frequency distribution map is drafted; (4), micro doppler distance units are determined; (5), echo separation of a distance unit; (6), it is determined whether all distance unit have been traversed; (7), a distance-doppler method is used to carry out imaging on a rigid body echo; and (8), imaging is carried out on a rotary part echo. According to the invention, a low frequency modulation rate matched filtering method is employed to carry out echo separation, so that an adaptive chirplet decomposition imaging method's disadvantages including large calculated amount, high time consumption and insufficience of real-time property are overcome; therefore, the method has advantages of simple realization, high efficient and high real-time property. According to the invention, an I-Radon conversion is employed to carry out imaging on a rotary part; therefore, defects of an EHT algorithm are overcome, wherein the defects include high image sidelobe of a rotary object, low precision of estimation position and inaccuracy of object identification; and the method has advantages of good image focusing, high position estimation precision and accurate object identification.

Description

technical field [0001] The invention belongs to the technical field of signal processing, and further relates to a two-dimensional ISAR imaging method for a micro-motion rotating target in the air in the field of radar imaging. The invention can effectively detect the micro-motion rotating target in the air, and accurately locate and image the target. Background technique [0002] When using Inverse Synthetic Aperture Radar (ISAR) to image micro-moving targets in the air, aircraft propellers, helicopter rotors, turbine engine blades, precessing missile warheads and other micro-moving rotating parts will affect the radar waveform within a certain range of attitude angles. Modulation is performed to generate a radar echo signal containing a periodic modulation component, that is, a micro-Doppler effect is generated, and its rotating parts will appear as a modulation interference band along the Doppler direction in the ISAR image, which will affect the ISAR image quality of the...

AI Technical Summary

Problems solved by technology

However, the disadvantage of this method is that because the EHT algorithm is affected by the point spread function, the obtained rotating target image will have high side lobes, and the estimated position accuracy is not high.

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