IMU/DGPS-supported Photogrammetry-Theory, Approaches And Practice

This dissertation summarizes and presents the basic principles, approaches and critical techniques and technologies involved in IMU/DGPS-supported photogrammetry. How to plan a calibration field? How to configure GPS base-station locations? How to deal with coordinate systems between WGS84 and a local system? Those three topics are discussed based on results of a number of exhibition experiments and real photogrammetric practice in China. Especially the combined accuracy is analyzed and verified in detail. A complete solution of IMU/DGPS-supported photogrammetry has been worked out within this research project and presented in the dissertation. This research project consists of following aspects:1. Base on a comprehensive survey of literature on the techniques and technologies involved in IMU/DGPS-supported photogrammetry and utilizing experimental research and real world production data, the dissertation describes the basic principles of positiona and attitude determination by using an IMU/DGPS system, the angle definitions in inertial navigation technique and photogrammetry, and their relationship, the components and applications of an IMU/DGPS system. Furthermore, the dissertation deals with transformations between different coordinate systems, computation of boresight misalignment angle and mathematic models in Integrated Sensor Orientation (ISO).2. The design scheme of calibration field is presented in this sissertation by analyzing the functions of a calibration field and carring out a lot of experiment about it.3. The paper presents the positioning accuracy requirements for airborne GPS in IMU/DGPS-supported photogrammetry. Taking some special situation of China into account, the design scheme of differential GPS base stations is discussed. An optimal solution, i.e. Continuous Operational Reference Station (CORS) simultaneous observation method, is presented for computing accurate coordinates of base station positions in the paper and has been tested and proved in the practice. Some experiments were carried out to find out the correlation between DGPS positioning accuracy and the distance from GPS ground station to the airplane. Based on the above study, the optimal solution for DGPS calculation is suggested.