基于系统结构几何的卫星摄影测量联合平差及其应用效能研究

With fast development of space-borne camera and other load equipment technology, New type space-borne photogrammetry system can not only obtain high-resolution ground images, but also record other kinds of high-precision observation data such as the spatial position, attitude and distance between satellite and ground. However, Current satellite photogrammetry adjustment methods rely on camera images and ground control point observations, which are difficult to overcome the strong correlation among photogrammetry parameters caused by the minimal field angle of space-borne camera. This project will make an in-depth analysis on satellite structural geometry and establish the geometry correlation expressions among different observation devices. Then we can derive several new kinds of error equations of satellite original observations, on which the satellite photogrammetry multi-observation combined adjustment model can be built. We will also research the optimization methods of additional parameters selecting, automatic weight determination and fast solve algorithm of large normal equations. Simulation experiments show that the parameter correlation coefficients significantly reduced using combined adjustment model and a geopositioning result better than 1 pixel resolution can be achieved without using any GCPs. The research result can be applied in space-borne camera system calibration and triangulation to get high accuracy geopositioning result. The research can also provide a valuable reference for design and development of next generation space-borne surveying system.

随着星载对地相机及其他载荷观测技术的发展，卫星摄影测量系统不仅能获取高分辨率地面影像，还可以记录卫星在轨空间位置、姿态、对地距离等多种高精度观测数据。而卫星摄影测量平差基本模型依赖于地面影像和控制点观测值，无法从根本上克服由于高分辨率相机视场角极小造成的参数精确求解困难。本课题结合卫星系统工程学和解析摄影测量的理论方法，以系统结构几何参数为纽带，将卫星系统中多个独立的观测载荷本体连结成一个整体，进而揭示出各载荷观测量之间的内在关联，导出各类观测量的误差方程，建立严密的卫星摄影测量联合平差模型，并对其附加参数选择、自动定权、快速求解等具体方法进行优化。模拟试验表明，联合平差模型中参数相关性显著降低，无控制点平差定位精度可达到优于1个像元地面分辨率水平。课题研究成果可望应用于卫星摄影测量系统在轨精确检校和空中三角测量，同时可为新一代遥感测绘卫星系统的设计研制提供参考依据。

随着载荷研制技术的发展，测绘卫星观测系统所采集的观测值类型更加丰富、观测频率和精度也不断提高。为充分挖掘卫星原始观测数据的精度潜力，提升卫星测绘应用效能，本项目提出了基于系统结构几何的卫星摄影测量联合平差方法，并实现其数据仿真和平差处理软件。主要研究成果包括：（1）建立广义摄影测量系统的基本平差模型，相比常规定向片模型平面定位精度可提高14.8%，高程定位精度提高19.7%；（2）采用姿轨观测值辅助卫星摄影测量平差模式，相比基本模式平面定位精度可提高19.4%，高程定位精度提高71.3%；(3)采用激光测距值辅助卫星摄影测量平差模式，可在无控制点情况下大幅改进高程定位精度，相比基本模式可提高92.6%；（4）提出一种可适应多种几何畸变的二元傅里叶系统误差模型并引入卫星摄影测量联合平差模型，其对于复杂畸变的拟合精度明显优于常用一般多项式模型；（5）对基于系统结构几何的卫星摄影测量联合平差模型进行了全面的应用效能分析，给出不同观测条件下的影像对地定位和影像定向精度统计结果，提出对应不同场景的参考平差模式建议。本项目方法较常规方法在理论上进一步拓展，可充分利用测绘卫星原始观测数据并进行一体化平差，实现少量控制点情况下的高精度测绘卫星系统定向和对地目标定位，提高卫星摄影测量技术的应用效益。