Statistical Properties Of The Pulsed Laser Ranging Radar Echo Signal

Laser detection technology is one of the most important aspects of laser technology. Due to its high brightness,good directionality and monochromaticity, laser is playing more and more important part in national defense and civil field. As a type of laser detection technology, pulse laser detection is becoming the hotspot of global research. Based on the research of laser radar, this paper discusses how the signal property influence the detection performance.In the term of theory and design, this paper studies several kinds of laser detection technology in-depth, analyses the echo signal of pulsed laser and establishes the equation of signal to noise and distance. On this basis, we derive the equation of echo signal power and system noise. Quantitative analysis is done to the three major receiving system noise, and we study how the receiving aperture and receiver field of view affect the detection SNR. In design, we use large aperture lens to enhance the signal power, use avalanche photodiode (APD) as a photoelectric detector, using interference filter and the field diaphragm to reduce system background noise to improve signal to noise ratio of echo signal. The pre-amplifier uses transconductance circuit structure, which effectively amplify the weak output current of APD.In the term of experiment, we discuss how the amplitude of the echo signal influences the detection error and uncertainty. We find the detection error and uncertainty decrease as the amplitude of the echo signal goes up. And we do some experiment analysis on the rise-time of the echo signal, only to find the Gaussian distribution of the rise time, and the width of the signal is broadened. Then we further study how the system bandwidth has an effect on the system detection probability and rate of leakage detect. This paper improves the detection theory of pulse laser detection, and has a good reference value to the follow-up systems.