Weak Signal Detection Method in a Stronger Noise Background

When we use the laser auto collimation theodolite to measure the azimuth error angle of air target, the strong noise background reduces the spot imaging quality and seriously influences the measuring angle ability of the theodolite. In order to solve the problem, a photoelectric detection system used to detect the weak signal is designed based the correlation detection principle and the principle of correlation detection technology is introduced. We use Simulink software presenting a simulation to the detection system and do a feasibility analysis. Finally, it’s proved that the photoelectric detection system could suppress the strong noise background, improve the SNR greatly and detect the weak signal effectively.