Efficiency testing method for the echo receiving system of laser ranging station

In laser ranging systems, the echo receiving optical system is responsible for receiving and processing the echo photons returned by the target. The efficiency of the system affects the detection capability of the entire laser ranging system. This paper presents a method for measure the efficiency of the echo receiving system without the need for additional measurement devices. The approach leverages the capabilities of single photon detectors and measuring photon flux from stars at varying zenith angles, the impact of atmospheric extinction on system efficiency is considered. Through this method, the reception efficiency of the laser ranging system at TianQin station was tested and compared with the measured values of mirror reflectance, ensuring the requirements for performance monitoring of the laser ranging system.