【作者】 董玉磊；

【导师】 高飞；

【作者基本信息】 合肥工业大学 ， 大地测量学与测量工程， 2007， 硕士

【摘要】 近些年来，全球定位系统(GPS)技术发展迅速、日臻完善，已经在许多领域得到了广泛的应用，创造了巨大的经济价值和社会价值。但是，GPS定位观测得到的观测成果通常是世界大地坐标系统WGS-84中的坐标或坐标差，而在实际应用中需要的往往却是地面点在国家坐标系和地方独立坐标系中的坐标。为了使GPS的观测成果在实际中得到应用，就必须进行坐标转换，求出转换参数，把GPS观测得到的WGS-84坐标转换成实际需要的国家大地坐标或地方独立坐标。高斯最小二乘法是一种解决坐标转换的传统方法，它主要是通过解算法方程组得到坐标转换结果。然而由于高斯约化过程中的误差积累及法方程组可能病态的问题，从而导致得到的结果精度不高，甚至产生不稳定的解，不能满足实际应用的需要。遗传算法在处理病态问题方面具有一定的优势，因此探讨用遗传算法求取转换参数、尤其是在法方程组病态的情况下求解转换参数具有重要的研究意义。本文首先介绍了有关GPS坐标转换的基础知识和GPS坐标转换常用的几种转换模型，并在此基础上分析了病态问题产生的原因和处理病态问题的一些传统方法。然后，阐述了标准遗传算法的理论知识和基本原理，讨论了标准遗传算法的不足之处和对遗传算法一些改进方式。最后，结合几个算例用改进的遗传算法实现了对病态方程的处理，并与传统方法的计算结果进行了比较，得到了满意的结果，从而验证了改进的遗传算法处理病态问题的可行性和有效性。更多还原

【Abstract】 In recent years, Global Position System (GPS) technology develops rapidly and becomes more and more consummate. It has been widely used in many fields and created gigantic economic value and social value. The observation results using GPS are the coordinates or coordinate differences in World Geodetic System (WGS-84), but in practical using the coordinates of floor points system in national coordinate system or in local independent coordinate system are required. So in order to use GPS coordinate, we need to calculate the geodetic coordinate transformation parameters and transform the coordinates in WGS-84 that get from GPS observation to the coordinates of national coordinate or local independent coordinate which we need in practical engineering. The traditional way is using the least-squares method to get the transformation results by processing the normal equation group, but the accuracy of the results may be not very high and even they are unreliable for erroneous accumulation in Gauss melt process or the condition that the normal equation group is ill-conditioned, which can not satisfy the need of the practical application. Genetic algorithms have certain superiority in processing ill-conditioned problem. Therefore, exploring to use the genetic algorithms to get transformation parameters particularly in the condition that the normal equation group is ill-conditioned has the important research significance.In this paper, it firstly introduces some basic knowledge about GPS coordinate transformation and several transformation models in GPS coordinate transformation, in this foundation it analyzes the reason which the ill-conditioned questions produce and presents some traditional methods of processing ill-conditioned questions. Then it introduces elementary knowledge about genetic algorithms and its basic principle, discusses the existent deficiency of simple genetic algorithms and some improved ways to the simple genetic algorithms. At last, using the improved genetic algorithms realizes solving the ill-conditioned problems with several examples, and gets the wanted results after comparing with other traditional ways. Thus the improved genetic algorithms have confirmed the feasibility and the validity in processing the ill-conditioned questions.更多还原