考虑定向参数精度信息的TerraSAR-X和SPOT-5HRS影像RFM联合定位

卫星影像的RFM模型具有传感器无关的优点,适用于多源影像的几何定位处理,但在无地面控制点条件下联合定位时存在自主定位优势影像难以发挥主导作用且求解易发散的不足。本文通过将影像的先验自主定位精度和成像线性漂移转化为像方定向参数的精度和权信息,建立考虑影像定向参数精度信息的RFM模型。以12景TerraSAR-X和6对12景覆盖面积约为18万km2的SPOT-5HRS立体长条带影像为数据源,对两类影像定向参数先验精度配置偏差、SAR影像升降轨道方向、SAR影像数目、SAR影像分布等因素对定位精度的影响进行了系列定位试验,少量SAR与大范围HRS联合的影像自主定位平面/高程精度可达6.0m/4.2m。本文RFM平差模型无地面控制点定位精度和定向参数求解稳健性相对于传统模型有显著提升,是卫星影像无控制点1∶10万/1∶5万全球测图的一种潜在方法。

Combined Positioning of TerraSAR-X and SPOT-5 HRS Images with RFM Considering Accuracy Information of Orientation Parameters

RFM is suitable for geometric positioning with multi-source images because of the independence of sensors.However,without GCPs the geometric advantages from the geometrically prevailing images cannot be enforced in the traditional RFM-based orientation.It also leads to the apparent flaw of divergence of solving.By translating the priori information of autonomous positioning accuracy and imaging drift errors to bias compensation parameters in image space,it is rebuild a new RFM-based adjustment model which considers the accuracy and weight of the orientational parameters.A test study of positioning without GCPs which includes 12 scenes of TerraSAR-X images and 6 pairs of long-strip stereo SPOT-5 HRS images covering area of 186000km2 is conducted.Furthermore,the different impact factors on positioning accuracy,i.e.,the accuracy of orientation parameters,the number of SAR image,orbit direction of SAR satellite and distribution of SAR images,are investigated.The results show that it can achieve positioning accuracy of 6.0 m in plan and 4.2 m in height for the case of geometrical combination of TerraSAR-X and HRS images.The proposed model is superior to the traditional RFM-based positioning with respect to accuracy and resolving stability.It is a potential approach for worldwide mapping at scale of 1:100000 and 1:50000 without GCPs by combination of different satellite images.