Analysis of detection capability of active laser detection systems

An active laser detection system could detect and recognize cat's eye targets at long distance. Detection capability analysis was the basis of system design. To assess the detection capability, a mathematical model of the system's signal-to-noise ratio(SNR) was established based on laser echo power. The dependence of SNR on several factors, such as receiving optical lens diameter, laser peak power, laser divergence angle, defocusing distance was quantitively analyzed. The results show that at a certain distance, the detector noise comes mainly from shot noise and background noise which surpass dark current noise and thermal noise at least 2 magnitudes. The most effective way to improve detection capability is to use lasers with small divergence angles. The result is helpful for the design of active laser detection systems.