【作者】 龚辉；

【导师】 姜挺；

【作者基本信息】 解放军信息工程大学 ， 摄影测量与遥感， 2008， 硕士

【摘要】 航天线阵CCD(Chorse Coupled Device)影像在遥感影像定位中具有广泛的应用,其摄影高度大,视场角小,光束窄,以致传统的线性化共线条件方程定向参数之间具有较强的相关性,很难得到稳定的高精度解。本文以四元数为工具,研究了四元数在摄影测量定位中的应用,对基于四元数的线阵CCD影像定位技术所涉及的病态问题求解、四元数描述外方位元素、四元数光束法平差等关键问题进行了深入研究,主要内容包括:1、研究了基于四元数的空间后方交会和绝对定向直接解法,提出了对偶四元数进行绝对定向的直接解法,把对偶四元数应用于描述绝对定向中的旋转和平移参数,成功进行绝对定向解算并进行对比实验论证。2、针对线阵CCD影像外方位元素求解中出现的病态问题,从理论上分析了其产生的原因,提出了一种解决病态问题的改进有偏估计新方法,用于求解线阵CCD影像的外方位元素。3、将四元数理论引入到线阵CCD影像定位中,用四元数描述其摄影姿态并构建旋转矩阵,借鉴EFP思想,提出了基于四元数的外方位元素改进EFP(Equivalent Frame Photo)模型,由此进行外定向并进行实验论证。4、将一幅线阵CCD影像首尾扫描行的外方位角元素用四元数描述,利用四元数球面线性插值(Spherical Linear Interpolation,SLERP)内插得到任意一扫描行姿态,提出了外方位元素的SLERP模型,推导出了相应的误差方程,并进行外定向计算,有效避免了欧拉角模型涉及的大量三角函数计算及不稳定因素,为线阵CCD影像外定向提供了一个新的技术途径。5、考虑到控制点数据可能存在粗差的情况,引入粗差探测,结合基于四元数的外方位元素改进EFP模型和SLERP模型进行外定向,并利用严密的空间前方交会进行定位实验,结果论证了算法的正确性及优越性。6、研究了基于四元数的线阵CCD影像光束法平差,该方法对平差初始值要求不高,只需取零初始值即可。实验结果表明平面的平差精度较高,高程精度稍差一些。更多还原

【Abstract】 Line-array CCD Images are widely used in positioning of remote sensing imagery. However, the orientation parameters of traditional linearization collinear equation are highly correlated because of such factors as big flying height, small angle of coverage, narrow light beam and so on, and thus, are fairly difficult to gain steady and precise solutions. This dissertation makes a comprehensive study on the subjects related to photogrammetric positioning of the line-array CCD images based on quaternion, which includes the solution of ill-posed problem, describing exterior orientation elements by quaternion, bundle block adjustment based on quaternion, etc. The followings are what we have done in this dissertation:1. Making a comprehensive study on the subjects related to photogrammetric positioning and close-form solution of absolute oritentaion based on quaternion, putting forward a new close-form solution method based on dual quaternion. Dual quaternion is introduced into absolute orientation to describe rotation parameters and translation parameters, and experiments were done in all these methods.2. Analyzing the reasons theoretically to ill-posed problems which are appeared in the process of solving exterior orientation elements, and putting forward an improved bias-estimation method to compute the exterior orientation elements of line-array CCD images in the aspect of computation methods.3. Using quaternion to describe the attitude elements of line-array CCD images in the aspect of model selection, putting forward an improved EFP model of exterior orientation elements based on the idea of Equivalent Frame Photo, and doing some exterior orientation experiments through the improved EFP model.4. Gaining the quaternion attitude elements of any scan line through the method of Spherical Linear Interpolation of quaternion, when quaternion is used to describe the exterior orientation elements of the first and the last scan line of a line-array CCD image, putting forward a SLERP model for exterior orientation elements, and then doing some exterior orientation experiments by SLERP model. It successfully avoids a great deal of computation of trigonometric functions and the potential unstable factors, provides a new technique for exterior orientation of line-array CCD image.5. Considering that there are some coordinate blunders in Ground Control Points (GCPs), a blunder detection method is used in the process of exterior orientation by the combination of quaternion improved EFP model and quaternion SLERP model, doing some positioning experiments by space intersection, and the experimental results verified the reliability and stability of these methods. 6. The quaternion-based bundle block adjustment of line-array CCD images is studied in this dissertation. Favorable initial values of computation parameters in bundle block adjustment are not required by this method, and the initial values can be assumed to zero. Experimental results indicate that the plane precision is very high, while the height precision is less admirable.更多还原