A three-beam all-fiber coherent FM continuous wave lidar

Abstract

The invention discloses a three-beam all fiber coherent frequency-modulated continuous-wave laser radar. The transmitting and receiving portions of the laser radar use all fiber light paths, the fibers are used as transmitting and receiving light paths of laser, and therefore a light source and a detector can be arranged away from a harsh ambient detection environment. The laser radar also has the advantages of simple structure, light weight and the like. Through utilizing three beams to irradiate a target, the three-dimensional velocity and the distance information can be simultaneously demodulated, and the dynamic error brought by swing is eliminated. A light beam emitted by the light source is divided into two light beams by a first coupler to be transmitted, and then the two light beams are divided into light beams in an X-axis, a Y-axis and a Z-axis for transmission by a second coupler and a circulator, so that the light beams irradiated on the target have three-axis light beam characteristics in a space coordinate system. The laser radar adopts a coherent detection method and a triangular wave frequency-modulated continuous wave system, the distance and speed information can be simultaneously detected, the problems that the distance velocity resolutions of a pulse system are mutually restricted are solved, and the non-blind-spot high-precision measurement is realized. Under the condition that the frequency error is introduced without the difference of lasers, the three-dimensional velocity and distance can be simultaneously measured to obtain the detector posture, and the dynamic error is reduced by 2 to 3 orders of magnitude.

Description

technical field [0001] The present invention relates to a laser radar, more particularly, to a fiber laser radar with three beams of coherent frequency-modulated continuous waves. Background technique [0002] The laser radar mainly works in the infrared and visible light bands. When the radiation irradiates the target, the laser radar uses the echoes generated by the target's reflection, refraction, scattering and transmission to detect the target. Compared with traditional microwave radar, lidar has a much shorter wavelength, so it has high detection sensitivity and high measurement resolution, all-weather work, small size, light weight, strong ability to integrate with the network, and can detect targets at the molecular weight level. advantages of detection. [0003] The basic composition of lidar includes three parts: transmission, reception and post-signal processing, and the mechanism that makes the three parts work in harmony. Refer to the content disclosed on page...

AI Technical Summary

Problems solved by technology

[0012] Since the current frequency-modulated continuous wave ranging lidar cannot measure the three-dimensional speed and distance of the target

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