Multi-wavelength synthesized aperture laser imaging radar

Abstract

The invention discloses a multi-wavelength synthesized aperture laser imaging radar. The multi-wavelength synthesized aperture laser imaging radar consists of a multi-wavelength chirp laser emitter and an optical heterodyne receiver which are in one time sequence, wherein the laser emitter periodically emits chirp laser pulse beams having different start wavelengths through one or more space channels; and the optical heterodyne receiver receives a target laser echo signal and performs image processing once so as to finally generate a target image of the aperture laser imaging radar and output the target image. The multi-wavelength synthesized aperture laser imaging radar effectively increases the receiving probability of the target laser echo signal and avoids the influence of the change of laser speckle strength.

Description

technical field [0001] The invention relates to a synthetic aperture laser imaging radar, in particular to a multi-wavelength synthetic aperture laser imaging radar. Background technique [0002] Synthetic aperture laser imaging radar (referred to as optical SAR) is the only optical imaging observation method that can obtain centimeter-level imaging resolution at long distances. Its principle is derived from the principle of synthetic aperture radar in the radio frequency field. The content is completely different, and the implementation methods and key technologies of optical SAR and microwave SAR are also completely different. The antenna of the synthetic aperture lidar imaging radar uses an optical telescope. When the optical antenna is used for laser beam emission, its divergence angle is equivalent to the diffraction angle of the antenna aperture. When the optical antenna is used for optical heterodyne reception, its receiving field angle is also equivalent to the diffr...

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Problems solved by technology

The amplitude fluctuation shows that the echoes of the target distribution unit are randomly distributed speckle, and the average scale of the speckle is equal to the scale of the diffraction spot of the resolution unit scale aperture, so the average area of ​​the speckle is larger than the area of ​​the receiving antenna, because the central position of the speckle The uncertainty of the optical receiver antenna may receive the speckle signal or may not receive the speckle signal at all, which will seriously affect the imaging quality

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