The Study On Echo’s Detection Probability Of Photoelectric Systems Based On Cat’s Eye Effect

At present, for the vast majority of photoelectric systems, their focal plane of theoptical system is always equipped with an optical detector. When the light radiationconverged by optical system is absorbed with high sensitivity optical detector, itwould not be fully absorbed by the detector, a considerable part of the light radiationenergy will be reflected back the same way, and the intensity of reflection echo is2-4times than the diffuse echo of the general background. This physical feature is called"cat’s eye" effect. Laser active detection technology uses the target’s "cat’s eye" effect,launches probing laser beam toward the target area, and processes the target’s echosignal caused by optical lens to achieve the purpose of identifying targets. Since theecho signal produced by the optical system "cat’s eye" effect has high SNR, therefore,in the long-range detection, compared to the traditional detection technology, Thelaser active detection technology has higher detection accuracy, and the detectionspeed is more quick.In the long-range laser active detection, we usually issue pulsed laser. Compared tothe continuous laser, pulsed laser’s instantaneous power is strong, so it has farerdetection distance. When the target’s optical system is irradiated by pulsed laser, theproduce conditions of echo is subjected to the type of the detector of objectives: If thedetector is staring probe, it always has "cat’s eye" effect and the incident laser pulsecan be reflected back all the time; else, if it’s scanning probe, only when both theprobe scan the instantaneous field of view and pulse laser irradiate the detectorhappen at the same time, the target has "cat’s eye" effect and generate the echo. Thus,in the long-range detection, if we issue pulsed laser to detect the scanning target, theresult of echo detection is uncertain.At present, lots of research in related aspect of laser active detection usuallysimplified the generation conditions of the target’s echo. They always detect thestaring photoelectric system by issuing continuous laser, but lack the consideration ofusing pulsed laser to detect scanning optical system. For the deficiencies of thedomestic research, the point of this paper is focus on the generating conditions oftarget’s echo, and we describe the quantitative detection results for the scanningphotoelectric systems by introducing the concept of probability. This main work of this paper can be concluded as following three aspects: First, wedescribed the echo generation mechanism of scanning photoelectric systems with thecondition of irradiation by pulsed laser, and combined with the corresponding echosimulating experiments, we analyzed the root cause of the uncertainty detection resultof target’s echo; Secondly, according to the mathematical definition of probability, weproposed the method of analyzing the detection probability of echo of scanningphotoelectric systems, and improved the detection probability by relevant simulatingexperiments; Finally, we designed and implemented the verifying experimental tovalidate the results of simulating experiments with the same conditions.