Using GPS/INS data to enhance image matching for real-time aerial triangulation

•An image matching system that well suits real-time AT is presented.•We present how GPS/INS data are used to enhance KLT algorithm.•Error propagation is used to find number of pyramid levels for KLT tracking.•We compare the accuracy and speed between the original KLT and the proposed work.•The proposed system can improve the accuracy of EOs acquired from GPS/INS sensors.

Direct georeferencing is a promising technique for determining the exterior orientation parameters (EO) of a camera in real-time through the integration of GPS/INS sensors. Instead of using expensive devices, we improve the accuracy of the directly measured EOs through aerial triangulation (AT) and rely on tie-points. In this work, using GPS/INS data, we enhance the KLT tracker to achieve accuracy and speed that is compatible with real-time aerial triangulation. Given GPS/INS data from medium-grade sensors, the proposed system is 48% faster than the original work and tie-points extracted by our system are 6.33% more accurate and more evenly distributed than tie-points extracted by the original work. The AT processing results show that tie-points from the proposed work can reduce the RMSE of the directly measured EOs by 17.87% for position and 23.37% for attitude. Thus, we conclude that our proposed system can be integrated with real-time aerial triangulation.