Research On The Detection Performance Of Gm-APD Laser Radar With Pulse Accumulated Detection

With the development of technology, laser radar has been widely used in manyfields, like military, astronomy and industry, it has been a member of the high-techfields. Because of single photon sensitivity of Gm-APD(Geiger-Mode of AvalanchePhotodiodes), it has a great advantage in the weak signal detection withhigh-precision and long-distance. The three-dimensional imaging laser radar uesdGm-APD arrays has developed quickly over the past decade. This paper studies theGm-APD laser radar with pulse time-of-flight ranging, researches the probability ofdetection and false alarm, and the range accuracy of the system with pulseaccumulated detection. Several measurs to improve the detecion performance of thelaser radar have been given.Firstly, this paper describes the resarch status of Gm-APD laser radar, andmake the contents of this paper be clearly. This paper introduced the basic principlesand model of Gm-APD, the time interval is divided in many bins and use Poissonstatistical theory to analyze avalanche probability of Gm-APD. The figures ofsystem structure and woking process have been given.Secondly, the paper studies the detection performance of laser radar with pulseaccumulated detecion both in the case of long-deadtime and short-deadtime. Themeasuring method of most value and half a threshod value with pulse accumulateddetection have been given. In the case of long-deadtime, the paper studies theprobability of detecion and false alarm by most value method with pulseaccumulated detecion, analyzes the influences of the accumulated times, signalstrength, and the opening time of strobing gate to the detection performance. Both inthe case of long-deadtime and short-deadtime, the paper studies the probability ofdetecion and false alarm and range accuracy, by half a threshod value method withpulse accumulated detecion, analyzes the influences of the accumulated times, andtransmissivity of attenuator to the detection performance. The conclusion is thatthere are a certain range of transmissivity of attenuator, which can make thedetection performance of the laser radar to achieve the best. In the case oflong-deadtime, when the transmissivity of attenuator is controlled between0.33and0.20, the range is1.5km, the probability of detecion can become to double, and therange accuracy can be raised to cm from m magnitude scale. In the case ofshort-deadtime, when the transmissivity of attenuator is controlled between0.43and0.20, the range is1.5km, the probability of detecion can be improved25percent,and the range accuracy can be raised to cm from m magnitude scale. Later, it alsostudies the influence of deadtime. Finally, this paper uses MATLAB to constuct several parallel plate target model,and does a imaging simulation to the target model by32×32Gm-APD arrays laserradar to verify the conclusion of this paper.