Study On Lunar Topography Surveying And Mapping Based On Lunar CCD Imagery And Laser Altimeter Data

The moon exploration is the beginning of China’s deep space exploration. In the thesis,based upon the scientific exploration data obtained by the first China independently developedlunar exploration satellite-Chang’e-1, the study work was carried out around the lunar surfacetopography mapping problems. Research work was put on the lunar CCD images and laseraltimetry data combined photogrammetry theoretical and technical issues, Chang’e-1CCDimages and laser altimetry data combined positioning model, the lunar surface block adjustmentassisted by laser altimetry data, stereo image matching technology for information-poor lunarsurface and lunar DEM automatically generation, and other key technologies and methods. Themethods proposed in the thesis were supported by the preliminary experimental validation. Themain work and innovative achievements were listed as follows.1. The imaging model of Chang’e-1linear array CCD image assisted by laser altimetrydata was studied. Aiming at the multicollinearity problem existed in the strict imaging model,several ways were discussed to overcome the multicollinearity, Ridge estimation method, thespectrum correction iteration method, the quaternion representation for diagonal elements.Through experiments, conclusion were obtained that three methods have equivalent precision,Quaternion method greatly reduces the trigonometric functions computation, and the Ridgeestimation and spectrum correction iteration method have significant geometric meaning.2. Laser altimetry data was using as observed value in orientation parameter calculating,laser altimetry data and image registration algorithm was presented. Forward intersectionpositioning was realized for the lunar surface target point, and related test was carried out usingthe CCD images and laser altimetry data obtained by the Chang’e-1.3. The orientation piece image interpolation was introduced. Large area block bundleadjustment was realized for lunar surface based on the strict imaging model and theexperimental results were satisfactory.4. Vertical Line Locus （VLL） was used in lunar block adjustment, laser altimetry pointsas image connection points automatic extraction was realized, large number of connectionpoints was provided for adjustment, stability and reliability of calculation was guaranteed.Experimental results proved that compared with single model orientation the precision wasimproved more than50%.5. Projection trajectory method was used to analyze the basic characteristics of the epipolarline in the linear array CCD image. A matching method based combined character and multi-restriction was proposed for Chang’e-1CCD image. First, feature matching wasconstrained by minimum Euclidean distance and the quasi-epipolar, the least squares matchingand combined adjustment model was formed by combining the least squares matching theoryand the matching model to improve the image matching accuracy. Then, fine image matchingwas realized by using the Harris point6. It realized full lunar digital topography model (DEM) generation method based highprecision matching algorithm. Interpolation, accuracy statistics and other key points in DEMgeneration were studied, and the adaptive multi-knot spline interpolation method was proposed.