Laser radar of double-wavelength for adaptive range gate

Abstract

The invention discloses laser radar of double-wavelength for an adaptive range gate. The laser radar comprises a laser source (1) of double-wavelength, an optical delay (2), a transceiver optical system (3), a beam splitter (4), a linear detector (5), a double -mode signal processing module (6), and gating circuit (7), single photon surface array detector (8), and three-dimensional image processing module (9). According to the laser radar of double-wavelength for an adaptive range gate, the effects of dual modes of linear detection and single photon detection are mutually complementary. Targetdistance information is rapidly acquired by the linear detection as an opening signal of the real-time adaptive range gate of the single photon surface array detector, and the range gate changes withthe target, so that the influence of backward scattering and background noise is reduced, and the efficiency of the single photon surface array detection and the working efficiency of the radar system are improved. The double-wavelength data is fused so as to improve point cloud precision and target identification and classification capability.

Description

technical field [0001] The invention belongs to the technical field of photoelectric imaging, and relates to a dual-wavelength self-adaptive range gate laser radar. Background technique [0002] In the detection process of targets under the jungle, occluded targets, underwater targets, etc., the echo signal is very weak, the sensitivity of the linear detector is low, and only the unit or small area array can be used for detection, and the work efficiency is low; generally, high-sensitivity single photon is used Area array detectors have high data acquisition efficiency and high ground resolution, but the high sensitivity makes noise suppression more difficult, and it is easy to be triggered by noise to generate false alarms; single-photon detectors have a dead time and require multi-pulse cumulative detection. In this way, the range-gated laser imaging technology is introduced to suppress backscattering and background noise, and improve the target signal-to-noise ratio. Gene...

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Problems solved by technology

[0002] In the detection process of targets under the jungle, occluded targets, underwater targets, etc., the echo signal is very weak, the sensitivity of the linear detector is low, and only the unit or small area array can be used for detection, and the work efficiency is low; generally, high-sensitivity single photon is used Area array detectors have high data acquisition efficiency and high ground resolution, but the high sensitivity makes noise suppression more difficult, and is easy to be triggered by noise to generate false alarms; single-photon detectors have a dead time and require multi-pulse cumulative detection

In this way, the range-gated laser imaging technology is introduced to suppress backscattering and background noise, and improve the target signal-to-noise ratio. Generally, the range gate switch is fixed. For dynamically changing targets or the laser radar is located on a moving platform, in order to ensure the farthest and closest targets All can be detected, and the range gate setting generally requires a long time, which reduces the detection efficiency and reduces the advantages brought by the range gate technology. Therefore, it is necessary to adaptively adjust the opening time of the range gate according to the change of the target distance, thereby reducing the range gate control time.

In addition, single photon detection is a cumulative probability detection process, and the distance information can also be obtained through the accumulation of multiple pulses in the front, which can be used as a reference for the opening signal of the distance gate. However, for the detection process with relative motion, the reference will lag, especially In areas with large terrain gradient changes, there may be loss of target data

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