Echo Characteristics of Satellite Laser Ranging Based on Geiger Mode SPAD

Based on the photoelectric properties of Geiger mode single photon avalanche diode, the effect of laser pulse width and echo intensity on the satellite laser ranging system range precision is analyzed, and the geodynamics satellite is observed by the satellite laser ranging system of Changchun station. The results indicate that when the number of echo photon is about 1 000, the system ranging precision is about 10.2 mm, while the number of echo photon is about 8 000, the system ranging precision is about 9.4 mm, it shows that stronger echo intensity can improve the system ranging precision. When the laser pulse width is 200 ps, the precision of the system is 17.3 mm, while the pulse width is 50 ps, the system ranging precision is 10.0 mm, it indicates that the system range precision is effectively improved with the narrow pulse width. In order to further verify the theoretical conclusion, the Ajisai satellite is observed. The effect of high repetition frequency laser ranging system on the range precision is analyzed. It shows that by using the narrow pulse width and high repetition frequency system, the returns and data density per normal points are greatly increased and the range precision is also improved. Therefore, to improve the echo characteristics of satellite laser ranging system, the high quality laser with narrower laser pulse width, higher frequency and larger energy should be selected as a laser light source of satellite laser ranging system based on the Geiger mode single photon avalanche diode.