中文摘要：

几何精度衰减因子GDOP和卫星信噪比SNR等多方面因素的影响，增大了GPS单点定位误差。根据实测GPS数据，选取了对定位精度影响较大的两个因素GDOP和SNR，对它们与定位精度之间的关系分别进行研究；基于模糊算法建立了由GDOP和SNR估计定位精度的模糊规则数据库；通过试验数据验证了该模糊规则数据库的有效性和实用性。

英文摘要：

GPS positioning accuracy is influenced by Geometric Dilution of Precision （GDOP）, Signal Noise Ratio （SNR） and so on. As GDOP and SNR influence the GPS result obviously, the relationships between them and the precision of GPS were researched separately based on GPS data. Based on Fuzzy arithmetic, a database to evaluate the precision of GPS was introduced. The validity and practicability of this database were proved by experiment.