A detecting and compensation method for the errors from broken ground control points at the application of Direct Geo-referencing

This paper proposed an automatic method to detect and compensate the broken GCPs at the application of Direct Geo-referencing. Initial exterior parameters were from the aiding of GNSS/IMU integration through a 15-state Kalman Filter, the detecting method is based on Aerial Triangulation and an enumerating way. The correction of broken GCPs is calculated by forward intersection. Six aerial images taken from a town at Portugal and simulated broken GCPs were used to validate this method. The results show that this detecting method of the broken GCPs at the application of Direct Geo-referencing has a positive effect: the error caused by the broken GCPs can be decreased significantly.