Relative INS/GNSS aerial control in integrated sensor orientation: Models and performance

In this paper we present the models and discuss the performance of relative position and attitude INS/GNSS aerial control observations in integrated sensor orientation. In relative aerial control, we use the relative position and attitude of the IMU at the exposure times of successive images instead of the usual absolute position and attitude for each image. With relative aerial control, the GNSS shift correction parameters and the IMU-to-camera boresight matrix vanish from the functional models and so does the problem of their selection. The presented models are formulated with the usual original INS/GNSS attitude parameterisation (heading, pitch and roll) to avoid unnecessary and error-prone intermediate re-parameterisation steps. Furthermore, we present a rigorous model formulation, for both aerial control and photogrammetric observations, in local mapping coordinate systems that eliminate the need of the so-called height and azimuth corrections and that guarantee geodetic correctness and consistency. The overall resulting modelling scheme allows for a direct incorporation of INS/GNSS aerial control observations into the integrated sensor orientation processing chain in a simple and robust way. The performance of the new models is evaluated with three independent data sets and the results show a comparable to better performance.