摘要
作者从算法和过程的效率、自动化水平和数据的完整性入手，简要分析了传统算法中存在的问题。在此基础上，以提高自动化水平为目的，将地理实体多边形拓扑关系的建立过程归结为：弧结点的匹配和弧连接关系的建立；同一结点上弧－弧拓扑关系的建立；闭合边界弧段相邻关系的建立；闭合边界包含关系的确定等主要步骤。给出了各主要步骤的算法，并对提高算法效率也提出了新的改进方案。分析与试验表明：新算法对于减少人工操作次数提高自动化水平，提高交互输入地理实体多边形编码数据的完整性是有利的。
The biased estimation problem in free net adjustment model is considered when linear dependence and multicollinearity among the columns of the coefficient matrix exist simultaneously. A class of biased estimators are defined by introducing the canonical form of the rank deficient Gauss Markov model. The feature of our approach is to reduce the biased estimation problem in the rank deficient Gauss Markov model to the one in the rank full Gauss Markov model. Some important properties are discussed. As special cases of our class, seven known biased estimators are extended to the rank deficient Gauss Markov model, where the optimal values of the biasing parameters are determinated through the rank full canonical model. At last, a numerical example is presented.
出处
《测绘学报》
EI
CSCD
北大核心
1997年第3期254-260,共7页
Acta Geodaetica et Cartographica Sinica
