Research on the influence of pointing error on effective echo intensity and walk error of lunar laser ranging

• A coarse and fine two-stage pointing correction model is developed to compensate for the pointing error generated by the refractive index of the horizontal atmosphere. • Study of lunar laser ranging walk error and error compensation to improve ranging accuracy. The pointing accuracy of the laser ranging system is one of the most important parameters affecting the lunar laser ranging (LLR) detection capability, ranging accuracy and ranging precision. This paper first examines the sources of the pointing errors and models the effect of pointing errors on detection capability and walk error. Secondly, we establish a coarse and fine two-level pointing correction strategy, and correction of pointing errors due to changes in the refractive index gradient of the horizontal atmosphere. The pointing accuracy of LLR is better than 2″ by using coarse and fine pointing correction strategies. Then, based on an avalanche photodiode detector (APD) detector, the relationship between pointing errors and effective echo intensity and walk error is studied respectively. Finally, we use LLR data for validation analysis. The results show that the LLR effective echo is typically low, and after correcting for pointing errors (to ensure that LLR can be realized), small changes in effective echo rate does not produce large walk error, the walk error is on the order of millimeter to centimeter.