The TianQin Project is aiming at gravitational wave (GW) detection in space. TianQin GW observatory comprises three satellites orbiting on $1 \times 10^5$ km Earth orbits to form an equilateral-triangle constellation. In order to minimize the variations of arm-length and breathing angle, the satellites must be launched and adjusted precisely into an optimized orbit. Therefore, satellite laser ranging must be used to enhance the precision of satellite’s orbit determination. To develop the capability of satellite laser ranging for TianQin’s orbit, the TianQin Laser Ranging Station has been designed and constructed to perform high-precision laser ranging for TianQin satellites and lunar laser ranging as well. Applying a 1064-nm Nd:YAG laser with 100-Hz repetition frequency, 80 pico-second pulse duration, and $2 \times 2$ array of superconducting nanowire single photon detectors, we have obtained the laser echo signals from the five lunar retro-reflector arrays, and the measurement data have been packaged into 234 normal points, including a few data measured during the full-moon lunar phase. Each NP is calculated from continuous measurement for about ten minutes and the statistical error of the normal points is about 7 mm (1$\sigma$).

High-repetition-rate lunar laser ranging (LLR) has great prospects and significance. We have successfully obtained the effective echo signals of all five corner-cube reflectors (CCRs) on the lunar surface by using a 100 Hz repetition rate. This method can effectively improve the detection ability but has some defects: for example, the main wave and echo signals overlap. In this paper, the frequency selection and signal overlap are theoretically analyzed. The results show that the existing target prediction accuracy can meet the requirement of a 100 Hz repetition rate LLR. In the experiment, the use of a high-repetition-rate pulse laser allowed us to obtain detailed CCR information, such as the column number of CCRs, which will prove that the effective echo signals of LLR are reflected by the CCRs. Finally, we propose to use the resolved data to calculate the precision of inner coincidence and believe the accuracy can be within a millimeter.

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