Photon Counting Lidar with Combined Pulse Ranging and Its Ranging Method

Abstract

The invention discloses a photon counting lidar capable of realizing combined pulse ranging and its ranging method. The lidar includes a ranging management terminal, a timing control circuit, a laserdriving circuit, a pulse semiconductor laser, a transmitting optical system, a receiving optical system, a Geiger mode APD module, a distance gate circuit, a control transmitter, a timing circuit anda counting circuit. Through the combination of laser pulse transmitting and receiving, together with low-pass filtering and combined pulse recognition, high-precision photon counting ranging is realized. The invention can realize combined pulse correlation photon counting and ranging, and has outstanding advantages of long range, high ranging accuracy and good real-time performance, and is especially suitable for ranging and imaging of short-range high-speed targets.

Description

technical field [0001] The invention relates to photon counting laser radar technology, in particular to a photon counting laser radar capable of realizing combined pulse ranging and a distance measuring method thereof. Background technique [0002] Lidar has the advantages of high angular resolution, high distance resolution, small divergence angle, etc., and is widely used in industrial production, aerospace, military and other fields. Lidar based on time-correlated single-photon counting has higher time resolution accuracy and detection sensitivity, and is one of the main development directions of contemporary lidar. Chinese patent 201510477918.X discloses a 4D imaging photon counting lidar based on complex modulation pulse coding. Through the signal generator, laser, transmitting optical system, receiving optical system, narrow-band filter, Gm-APD single photon detector, and signal processing module, the distance measurement of multiple combined pulses is realized and t...

AI Technical Summary

Problems solved by technology

This patent uses a signal generator to drive a single laser to generate a pulse sequence. Its disadvantage is that a large number of accumulation times is required to realize the amplitude difference of the photon count value, and it cannot be used for distance measurement when the photon count value is 1 after a small number of accumulation times.

At the same time, this method has high requirements on the performance of the laser, the interval of the pulse sequence is long and cannot be adjusted, and the laser cannot continuously emit laser pulses with short pulse intervals

Secondly, in short-distance ranging, the electromagnetic interference and backscatter of the subsequent transmitted pulses will cause a high false alarm rate, and the false alarm rate control under strong background noise cannot be achieved.

Therefore, the real-time performance is insufficient, and it is difficult to achieve accurate dynamic measurement of moving targets under strong background noise conditions

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