Asymmetric Phase Encoding Ranging Method for LiDAR System

Abstract

The invention discloses an asymmetrical phase encoding ranging method for a laser radar system. Typical phase encoding methods used in lidar systems place high demands on the system hardware. The steps of the present invention are as follows: the laser in the laser radar system emits a laser signal with constant intensity, and the modulator performs intensity modulation according to the modulation signal sequence; the modulation signal sequence adopts m sequence; the demodulator performs intensity modulation on the echo signal according to the demodulation signal sequence Demodulation; use gating mode to control the cumulative detection time and output of the detector; the detector outputs the accumulated signal to the signal processor; the order of the detector output signal shows the position of the correlation peak, so that the signal processor directly judges the demodulation The phase difference between the signal and the echo signal; according to the phase difference, the target distance is calculated. The invention adopts the asymmetrical phase coding method to measure the target distance, reduces the requirement of the system on the sampling rate of the detector, and reduces the calculation amount of signal processing.

Description

technical field [0001] The invention belongs to the field of laser radar, and in particular relates to an asymmetric phase encoding ranging method used in a laser radar system. Background technique [0002] The typical phase encoding method used in the laser radar system modulates the phase of the light wave carrier frequency signal according to the code source, and then transmits the phase encoded laser pulse signal. The laser signal reflected by the target is converged on the detector through the optical system, and the detector is converted into an echo The coded electrical pulse signal is sent to the signal processor together with the demodulation signal, and the correlation calculation is completed in the signal processor, and finally the distance parameter of the target is given. However, the detection of phase-encoded signals requires a high-speed detector to sample the signal quickly and the signal processor to process it quickly, which puts high demands on the syste...

AI Technical Summary

Problems solved by technology

However, the detection of phase-encoded signals requires a high-speed detector to sample the signal quickly and the signal processor to process it quickly, which puts high demands on the system hardware, especially when the system uses an array detector, the number of detector pixels is large , the total signal bandwidth of the array detector and signal processor is difficult to meet the requirements of real-time detection of the system

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