中文摘要：

GPS（Global Positioning System）观测难免受到各种因素的影响,虽然可以通过不同观测组合和改正模型予以消弱,但总有一定的残留误差对定位结果产生影响.基于精密单点定位理论,通过无电离层组合模型、高精度GPS卫星轨道、卫星钟差来削弱电离层延迟误差、轨道误差的影响,以不同采样间隔的观测数据,分析对流层延迟历元间差分结果的特性；分析不同采样间隔观测中,对流层延迟历元间差分值的变化,对流层延迟对历元间差分观测值的影响；残留误差对历元间差分结果、组合观测值的影响；残留误差在时间序列上的变化.

英文摘要：

Positioning results may be influenced by different unavoidable errors such as space correlation errors,time correlation errors and so on,though ionosphere-free combination model can somewhat diminish the effects of ionosphere delay,and the orbit error can be modified more or less by the precise orbit.Based on the theory of precise point positioning,the paper presents a dscussion on the characterization of troposphere delay by adopting the data collected in different sample intervals,and also analyses of the variation of epoch-difference values of troposphere delay with the variation of sample intervals.Finally,the paper presents a study of the effects of troposphere delay on the observation of epoch-difference,the effects of residual errors on the position-difference and observation combination,and the variation of residual errors with time.