Theoretical Modeling And Experimental Study On Light Receiver Noise Of Lidar

Lidar receiver is the core part that determines the performance of a lidar, which is usually composed of optic system, APD detector, preamplifier circuit and main amplifier circuit. In order to provide the basis for optimizing the parameters of the laser radar receiver, the noise characteristics are modeled and analyzed.Mathematical descriptions of noise characteristic for avalanche diode and mu-circuit are given, and the noise analysis model for lidar receiver is developed on these basis. The influence of background light, bias voltage and amplifier circuit parameters on the output noise of this receiving system is discussed and the optimal bias voltage is 202V in certain condition is obtained through a large number of numerical calculations. The influence is verified by setting up the experimental equipment for studying the noise characteristics of lidar receiver. Under the CFAR condition, the output noise power of lidar receiver is gradually increased with the increase of the bias light, and tends to be stable. In addition, it is also found that the output noise amplitude statistics well obey the normal distribution, the normal fitted R-Square is above 0.9888 in the experiment. However, there will be small possibility shot noise of high amplitude in the noise distribution under the circumstance of weak bias light. This is the main reason that the output noise power changes with the bias light under the CFAR condition.The result will provide the theory and experimental basis for controlling the noise and optimizing the parameters of the receiving system.