A Self-calibration Method for Systematic Errors of Photoelectric Theodolite

摘要

In order to calibrate and correct systematic errors of photoelectric theodolite in a dynamic observating process, a self-calibration method which is applicable to the situation of multiple photoelectric theodolites tracking a kinetic object synchronously is provided in this paper. It's fundamental principle is: applying B spline function with coefficients to be estimated to approximate object's trajectory, setting up a multi-theodolite observation equation set including the systematic errors model of measurements, and fusing all observation equations and measurements in a long time segment, then establishing a parameter estimation model which has great redundancy information about the object's trajectory (B spline coefficients) and systematic errors, and using the parameter estimation method to obtain the estimation of all parameters and systematic errors. Simulation results indicate that in a case of 3 photoelectric theodolites located suitably tracking a kinetic object synchronously, the mean difference between estimations and the simulative value of systematic error coefficients is less than 0.1 seconds of degree, and the standard deviation of the estimation error is less than 3.3 seconds of degree mostly. So systematic errors of the photoelectric theodolites can be calibrated and corrected accurately by using this method.