【作者】 马晓锋；

【导师】 韩玲； 汤晓涛；

【作者基本信息】 长安大学 ， 摄影测量与遥感技术， 2009， 硕士

【摘要】 航天摄影测量是快速高效获取全球基础地理空间信息的重要手段,其难点在于无地面控制条件下的高精度定位。本文在分析无地面控制条件下影响航天摄影测量定位精度主要因素的基础上,重点研究了摄站坐标、相机焦距以及星地相机相互姿态等的检测方法。论文的主要内容概括如下:1.在已知摄影像片内外方位元素的条件下,通过立体像对空间前方交会处理可以获取地面点的空间坐标。将立体像对空间前方交会公式进行改化,作为无地面控制条件下测定地面点空间坐标的精度估算公式,对进行航天摄影测量工程系统参数设计具有一定的指导意义。2.摄站坐标误差是影响无地面控制条件下航天摄影测量定位精度的重要因素。在地面建设高精度试验场,通过单张像片空间后方交会处理,可以对摄站坐标精度进行检测。利用模拟数据进行计算表明:采用单张像片空间后方交会的方法进行摄站坐标精度检测完全可行,检测精度与地面控制点的精度密切相关。3.相机参数是影响无地面控制条件下摄影测量定位精度的又一重要因素。在近似垂直摄影条件下,由于像片内方位元素与摄站坐标之间存在较强的相互性,单纯使用单张像片空间后方交会的方法并不能精确检测相机焦距变化值,引入激光测高数据作为约束条件,可以有效提高相机焦距检测精度。模拟计算结果表明:即使激光测高数据以及地面控制点数据均含有一定误差,使用这种方法仍可获得较高的检测精度;采用多片分别检测后取平均值可有效消除偶然误差的影响。4.使用航天摄影测量方法获取地面点空间坐标时,根据控制条件的不同,可以分为有地面控制、无地面控制、以及航线首端有地面控制的轨道外推等多种数据处理算法。在进行有地面控制数据或者航线首端有地面控制数据的控制定位时,增加摄站坐标以及像片姿态数据作为附加控制条件,可有效消除误差积累、提高最终成果的整体精度。更多还原

【Abstract】 Space photogrammetry is a quick and effective means of acquiring the global basic geographical space information, and the difficulty of which is the high-precision position without ground control points. On the foundation of analyzing the main factors which influence the Space photogrammetry’s position accuracy, this paper analyses researches the calibration methods of the camera station coordinates, the camera’s focal length and the satellite-earth camera’s inter-attitudes etc. The major contents are generalized as follows:1. On the condition of known camera photo elements of interior and exterior orientation, The ground points’ space coordinates can be required by the stereoscopic pair’s space intersection. It is of guidance meaning for designing the parameter of Space photogrammetry project to transform the stereoscopic pair’s space intersection formulation into a accuracy estimation formulation of measuring ground points’ space coordinates without ground control points.2. The camera station coordinates errors are the main factor which influences the photogrammetry position accuracy without ground control points. By Constructing high-precision test field on the ground and processing single photo space resection, Camera station coordinates precision can be calibrated. The experiment of the simulation data show that it is valid to calibrate the camera station coordinates’ accuracy by single photo space resection and that the calibration accuracy is correlated to the ground points’ accuracy.3. The camera parameters are another main factor of the photogrammetry position accuracy without ground control points. On the condition of approximately vertical photography, because of the correlation between the elements of interior orientation and the camera station coordinates, The camera’s focal length can’t be calibrated accurately just only by the single photo space resection. Introducing the laser measurement altitude data as constraints, The calibration accuracy of the camera’s focal length can be improved. The experiment on the simulation data indicates that: although there is some errors of the laser measurement altitude data and the ground control points data, by making use of this method. The higher calibration accuracy can be acquired; By taking the average values of the camera’s focal length values of multi-photo calibration as result, The influence of the accident errors can be eliminated effectively.4. Acquiring the ground points’ space coordinates by the photogrammetry methods, according to are different control conditions, there are several data process algorithms such as with ground control points, without ground control points and the orbit extrapolation with few ground control points at the first step of the air line. Applying with ground control data or with ground control data at the first step of the air line to control position, it is effective to eliminate the cumulative error and improve the whole accuracy of the final results by increasing the camera station coordinates and the photo’s attitude data as additional condition.更多还原