To improve the positioning accuracy of circular scanning airborne laser bathymetry system, a calibration method is presented in this paper. When the laser points are collected by the bathymetry system on the level area, they should be on the same plane. However, they are not coplanar because of systematic error and random error. So we try to fit the points to a plane, which may help to adjust the errors and then correct the point location.Firstly, the circular scanning airborne laser bathymetry positioning model is derived in the simple mode. The intersection of laser line and sea surface is simulated depending on the mathematical principles of line and plane intersection. Combined with the direction vector of laser line in the water got by the refraction principle, the sea floor plane mathematical equation is used to compute the location of the laser points. Then, the parameter weighted least squares adjustment model is derived with the prior variance introduced, which lays the foundation for the following computing of calibration model. Finally, the calibration adjustment mathematic model and the detailed computing process are derived. The simulation computing and analysis for the calibration process is presented, and some meaningful conclusions for the calibration are achieved.
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