High-precision laser spectrum ranging method based on optical comb

Abstract

The invention provides a high-precision laser spectrum ranging method based on optical combs. The high-precision laser spectrum ranging method comprises the following steps: s1, measuring target pulse flight time by using a double-optical-comb method; s2, carrying out Fourier transform on the double-optical-comb interference signal data to obtain spectral information; s3, performing normalization processing and absorption peak fitting on the signal spectrum; s4, calculating the atmospheric temperature and the gas pressure in the light path through the absorption spectrum; s5, correcting the air refractive index in the light path by using the obtained atmospheric temperature and gas pressure to obtain the corrected air refractive index; s6, calculating the target distance according to the corrected air refractive index. By utilizing the characteristic of wide spectrum range of the optical comb, on the basis of optical comb pulse flight time distance measurement, measurement of absorption spectral lines of water molecules in the atmosphere is simultaneously realized, atmospheric temperature and gas pressure information is obtained by utilizing spectral line fitting, the air refractive index is corrected in real time, and the distance measurement precision is improved; therefore, the problem of poor distance measurement precision caused by atmosphere uncertainty in the prior art is solved.

Description

technical field [0001] The invention relates to the technical field of laser ranging, in particular to an optical comb-based high-precision laser spectrum ranging method. Background technique [0002] Laser ranging is an important direction of lidar and remote sensing. It provides an indispensable technical tool for the research of basic disciplines such as surveying and geography, so it has important application value. Laser ranging technology is an active measurement method. Its principle is to transmit a pulse mode or continuous mode optical signal to the target object, and measure the target distance by detecting the time-of-flight or phase difference of the reflected light from the object. Laser has the advantages of good directionality, high time / space coherence, and energy concentration, which can make up for the shortcomings of microwave ranging technology in measurement accuracy and spatial directivity in applications. [0003] At present, there are various methods...

AI Technical Summary

Problems solved by technology

[0008] Aiming at the technical problem that in the existing outdoor ranging applications, the air refractive index is uncertain due to changes in atmospheric environmental factors, which affects the estimation of the propagation speed of light in the air, resulting in limited ranging accuracy. The present invention provides an optical comb-based High-precision laser spectrum ranging method, the method is characterized in that it can measure the pulse time of flight and atmospheric absorption spectrum at the same time, and correct the atmospheric refractive index in real time, avoiding the instantaneous refractive index uncertainty introduced by atmospheric environment changes and its impact on ranging Accuracy is limited, so high-precision laser ranging in atmospheric environments can be achieved

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