Dual-wavelength dual-pulse unambiguous laser ranging device

Abstract

The invention discloses a dual-wavelength dipulse non-fuzzy laser ranging device. According to the basic principle, two laser pulses with two wavelengths are emitted, time intervals of the two laser pulses are sequentially encoded, a receiving channel receives laser back waves with two wavelengths with a wavelength beam splitting method and transmits the laser back waves to two detectors respectively, and time measurement is conducted on the laser back waves; back wave time difference between the pulses with the two wavelengths is calculated, the time difference of the starting pulse corresponding to the current laser back wave is accurately decoded, and the distance of a target is calculated. The dual-wavelength dipulse non-fuzzy laser ranging device has the advantages that the two pulses with the two wavelengths and encoded time intervals are adopted for ranging, and remote high-repetition-frequency non-fuzzy laser ranging can be achieved.

Description

technical field [0001] The invention relates to a laser radar and a laser three-dimensional scanner, in particular to a dual-wavelength and double-pulse non-ambiguous laser ranging device, which can realize high repetition frequency, long-distance, and non-ambiguous laser ranging. Background technique [0002] In the field of laser radar and laser 3D scanner, the commonly used laser ranging methods mainly include time-of-flight pulse direct ranging method and phase measurement method. Phase measurements are often used for close-range measurements because the emitted laser power is low. For non-cooperative targets beyond 200 meters, the pulse time-of-flight ranging method is usually used. The distance ambiguity problem exists in the pulse time-of-flight method. In order to obtain accurate distance information, the product of the ranging distance and the laser repetition frequency must be less than half of the speed of light. For LiDAR for long-distance measurement, it is of...

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Problems solved by technology

However, when this method measures penetrating targets (such as vegetation measurement), it will cause code misalignment due to the generation of multiple adjacent echoes, resulting in wrong ranging information

Moreover, the double-echo signal encoded by the double-pulse laser reaches a ranging channel. Since the response time of the ranging channel usually reaches tens of nanoseconds, that is, the pulse distance interval is several meters, the pulse interval time needs to be longer, and the pulse interval is too wide. It also affects the efficiency of coding

Therefore, for the current high repetition rate laser ranging and laser 3D scanners, there is still a certain contradiction between the ranging distance and the laser repetition rate, which limits the speed of ranging and laser scanning

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