GPS是发展最早、运行最稳定的导航定位系统，它能为用户提供实时的导航定位服务。但是GPS的标准定位精度并不高，即使在取消了SA政策之后，其精度仍然不能很好的满足需求，因此需要建立差分系统提高定位精度。 国内许多省市也建立起了CORS系统来提供差分服务，但是配备各个CORS系统的设备对普通用户来说成本较高，彼此独立的CORS系统也限制了网络差分服务的覆盖范围。因此，本文对网络差分服务系统的原理、应用需求、系统设计、核心算法和数据模型等方面进行了研究，并以Android平台为例进行了实验，以期对建立一个通用的、易于基准站提供者和定位用户接入的网络差分定位服务系统提供一定的参考。主要研究内容包括： (1)总结了不同差分技术的原理，针对多基准站的差分定位以及网络差分中差分数据的预报给出了相应的模型。 (2)对网络差分定位服务系统进行了需求分析，并依此进行了系统的设计。 (3)对系统运行中涉及的数据类型进行了分析，对数据结构、数据库的设计、数据交换模型作了研究和阐述。 (4)以Android平台为例，开发了相应的软件对简单的差分服务的提供进行了实现。 建立通用的网络差分定位服务系统，将差分信息置于开放的Internet网络上。开发相应的软件使得基准站拥有者可以方便的接入系统提供差分信息，扩大差分服务的覆盖范围。同时开发相应的软件，使得能够连入网络的GPS设备能够以相对低廉的改进成本接收系统提供的差分定位服务。

GPS is the developed and most stable operation of the navigation and positioning system, which can provide users with real-time navigation and positioning services. However, GPS standard positioning accuracy is not high, even after the cancellation of the SA policy, its accuracy is still not very good to meet the demand, it is needed to establish a differential system to improve the positioning accuracy. In China, many provinces and cities also established the CORS system to provide differentiated services, but the cost is high for ordinary users to equip devices of each CORS system, independent of CORS system also limits the network service coverage. Therefore, in this article, the network difference service system principle, application requirements, system design, core algorithm and data model were studied. Then do an experiment on the Android platform as an example, providing a reference for establishing an universal network station difference positioning service system which is easily access the system for reference-station providers and location users. The main research contents include: (1)The principle of different differential techniques is summarized, and the corresponding model is given for the differential location of multiple reference stations and the forecast of the difference data in the network. (2)The demand analysis of network differential positioning service system is carried out, and the design of the system is carried out. (3)The data types involved in the operation of the system are analyzed, and the data structure, the design of the database and the data exchange model are studied and described. (4)Taking the Android platform as an example, the corresponding software is developed to realize the simple differential service. We can establish a general network differential positioning service system, and put the differential information on the open Internet network. The development of the corresponding software makes the reference station owners can easily access the system to provide differential information, expand the coverage of differential services. At the same time, the development of the corresponding software, so that the GPS device which is able to connect the network can receiving differential positioning services of system in relatively inexpensive update cost.