Laser Pointing Error Estimation Based on Energy Data of LOLA System
【Abstract】To obtain the lunar elevation with high accuracy, it is necessary to accurately estimate the pointing error of laser. During the on-orbit operation of the Lunar Orbital Laser Altimeter (LOLA), the laser pointing at night deviates from that during the daytime due to the large temperature difference between day and night. This study first establishes a theoretical model of the detector receiving energy when the spot deviates from the center of the receiving field of view. Then, it analyzes the theoretical relationship between the spot offset and relative received energy based on this model and puts forward an estimation method of laser pointing error based on spot energy. Subsequently, the energy data generated when LOLA passed through Aestuum region during the surveying orbit (12 months) is used and combined with the estimation method. Then, the laser pointing errors of LOLA at night in moon are estimated to be 140.62 μrad along the orbit and −413.17 μrad vertical to the orbit, which are consistent with the results derived from LOLA earth scanning experiment and orbital intersection altitude data.
【Keywords】 remote sensing; lunar orbital laser altimeter; on-orbit calibration; laser pointing error; energy data;
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