Accuracy determination and Visualization for image geo-correction

摘要

There is two main factor of High-Resolution Satellite Imagery(HRSI) geometry correction. Besides mathematical models, Ground Control Points (GCPs) has played a big role on rectification. As how to determine the effect of GCPs in image geo-correction, the accuracy estimation of the control points is the main form by means of statistics. Yet this existing method shows nothing more than the partial expression in the statistic level. With the development of visualization technology, using the technology of spatial visualization for the accuracy determination affected by the GCPs and the whole expression are discussed in this paper. Taken affine rectification model and conformal rectification model as example, the paper has mainly deduced the relationship between the accuracy of arbitrary point and the control points. The Inverse Distance relationship is the result, therefore interpolation method related to the result is used to interpolate spatial accuracy for the image geo-correction. Based on above, the visualizations of accuracy is put forward to give the detail description for the quality of image geo-correction and the effect of GCPs'precision, quantity and distribution. The case ofHRSI is adopted to give the explanation for the spatial visualization of accuracy of GCPs, and also some helpful conclusions are obtained for its availability. From the case, it can be obtained that the precision of control points after conversion in affine model is lower than that in conformal model according to the different scale parameters in x or y direction.