Crossover Analysis and Adjustment for Chang'E-1 Laser Altimeter Data

A preliminary result of crossover analysis and adjustment of Chang'E-1(CE-1) laser altimeter(LAM) data of the Moon is presented.With about 9.12 million altimetric points acquired by the laser altimeter,more than 1.4 million crossovers covering the entire lunar surface are derived after eliminating outliers of orbits and altimetric points.The distribution of crossover points,the differences of crossover and the relationship with time have been systematically analyzed.Least-squares crossover adjustments with four basis functions of time(trigonometric functions and polynomials) are developed and compared to reconcile the LAM data by minimizing the crossover residuals globally.In the studying area(0°N~60°N,50°W~0°W),the crossover residuals can be reduced from 62.1 m to less than 37 m with anyone of the four models.The artefacts are reduced and the quality of the DEM generated from the adjusted LAM data is improved accordingly.