Analysis And Research Of IMU/GPS Supported Aerial Photogrammetric Error Sources And Positioning Accuracy

This paper presents the basic principles,approaches and key technologies involved in IMU/GPS supported aerial photogrammetry.Based on this,it specially described the principle of two IMU/GPS supported aerial photogrammetry methods-direct geo-referencing and IMU/GPS supported aerial triangulation in detail.Then, the main error sources of IMU/GPS supported aerial photogrammetry are analyzed, and two calibration methods of the system error are brought forward. Finally,combined with the tests in regions difficult to set up ground control points, the precision is analyzed and verified. The main contents are as follows:(1) The basic principles and advantages of IMU, GPS and IMU/GPS combination are described,and coordinate system definitions in the inertial navigation and photogrammetry are described.(2) The principles of direct geo-referencing and system integration error are described, and quantitative analysis of changes in GPS lever arms caused by aircraft attitude changes is made.Besides,experiments are made to verify this change on the positioning accuracy.(3) The main sources of error in IMU/GPS supported aerial photogrammetry, system error calibration and its correction methods are discussed.In addition, the layout methods and principles of calibration field,control point layout programs and system error calibration method are analysed in detail.(4) The principle of IMU/GPS supported aerial triangulation and mathematical model are described in detail.Furthermore,a large number of tests are carried out in Nanao-Yangjiang and Yuhuan area and the accuracy they can achieve is discussed.