A Single Step Calibration Procedure for Imu/gps in Aerial Photogrammetry

System calibration is required in integrated IMU/GPS systems to account for the spatial offset and misalignment between IMU, GPS and camera frames; synchronization is to be maintained, to predict IMU/GPS position and orientation data at the mid-exposure time of the images. To this aim, measurement on the ground, complemented by a calibration flight over a test field, are performed. Depending on the mathematical model, a two steps or a single step procedure may be used to recover the calibration parameters. Within the OEEPE test “Integrated Sensor Orientation” the authors proposed a simple but effective two steps procedure, where calibration parameters are computed as a weighted average of the discrepancies between the EO parameters of the images derived from block adjustment and those computed from the IMU/GPS data. Here a new single step calibration procedure is presented, where the calibration parameters are explicitely inserted in the collinearity equations and the IMU/GPS data are considered as pseudo-observed quantities, replacing EO parameters as unknowns in the block adjustment. Applied to the same OEEPE data set , the new procedure yields the same results of the previous one, with less ground control points.