The Overcoming of the Overparametrization in Self-Calibrating Adjustment

The selfcalibrating adjustment with additional parameters is the most efficient method for the compensation of systematic errors in analytical aerotriangulation today. Unfortunately, introducing a comprehensive set of additional parameters can produce a bad condition for normal equations under certain geometry, so that the adjusted results are poorly determined. In this paper some ways for overcoming the overparametization are investigated which do not eliminate some additional parameters by means of a statistic analysis, which leads to computational diffiiculties in practice. The investigation indicates: ——If a twofold block with cross flight direction is used, and the adjustment is performed with free additional parameters, the determinability of additional parameters and the reliability of the system will both be acceptable. ——If the additional parameters are considered as weighted observations where the weights are determined by the signal-to-noise ratio. the overparametrization can be in many cases avoided. ——If all the unknowns by the principle of the Maximum-Posteriori-Estimation or Ridge-Estimation are considered as weighted observations with a small weight (e.g.p=0.005—0.001), the overdarammetrization will be able to be overcome in any case of our experiments efficiently.