Comparative Analysis of Different Approaches for the Incorporation of Position and Orientation Information in Integrated Sensor Orientation Procedures

The utilization of integrated GPS/INS for direct sensor orientation has received increasing attention by the airborne survey and remote sensing community in the past few years. The availability of high accuracy position and orientation information, obtained from the GPS/INS integration, allows the direct determination of the image orientation parameters without the need for ground control points. In direct sensor orientation, besides individual sensor calibration (camera, GPS and INS), the system mounting parameters calibration is also needed. More specifically, the geometric relationship between the sensors (mounting parameters) must be determined as well. Photogrammetric reconstruction using GPS/INS information can be performed using the following procedures: (i) Direct georeferencing and (ii) Integrated Sensor Orientation (ISO). In the direct georeferencing procedure, GPS/INS derived position and orientation information are used in a simple intersection procedure. In integrated sensor orientation, on the other hand, GPS/INS positions and attitudes are incorporated in a bundle adjustment procedure. The incorporation of position and orientation information in ISO procedures can be carried out using two different approaches. The first approach consists of extending existing bundle adjustment procedures with constraints (i.e., using traditional collinearity equations with additional constraints). In the second approach, GPS/INS information is directly incorporated in the collinearity equations. More specifically, the collinearity equations are modified to allow for direct incorporation of such information. In this paper, a comparative analysis between these different approaches, as it relates to the estimation of mounting parameters and photogrammetric reconstruction, is presented. The comparative analysis will be evaluated using simulated and real datasets. * Corresponding author.