One's position has become an important piece of information for our everyday lives in a smart city. Currently, a position can be obtained easily using smartphones that is equipped with low-cost Global Navigation Satellite System (GNSS) chipsets with accuracy varying from 5 m to 10 m. Differential GNSS (DGNSS) is an efficient technology that removes the majority of GNSS errors with the aid of reference stations installed at known locations. The sub-meter accuracy can be achieved when applying the DGNSS technology on the advanced receivers. In 2016, Android has opened the accesses of raw GNSS measurements to developers. However, most of the mid and low-end smartphones only provide the data using the National Marine Electronics Association (NMEA) protocol. They do not provide the raw measurements, and thus do not support the DGNSS operation either. We proposed a DGNSS infrastructure that correct the standalone GNSS position of smartphones using the corrections from the reference station. In the infrastructure, the position correction is generated considering the GNSS satellite IDs that contribute to the standalone solution in smartphones, and the position obtained is equivalent to the solution of using the range-domain correction directly. To serve a large number of smartphone users, a Client/Server architecture is developed to cope with a mass of DGNSS positioning requests efficiently. The comparison of the proposed infrastructure against the ground truth, for all field tests in open areas, showed that the infrastructure achieves the horizontal positioning accuracy better than 2 m. The improvement in accuracy can reach more than 50% for the test in the afternoon. The infrastructure brings benefits to applications that require more accuracy without requiring any hardware modifications.

中文翻译：

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适用于Android智能手机的新型DGNSS定位基础架构。

一个人的位置已成为我们在智慧城市中日常生活的重要信息。当前，可以使用配备了低成本全球导航卫星系统（GNSS）芯片组的智能手机轻松获得位置，精度在5 m到10 m之间。差分GNSS（DGNSS）是一项有效的技术，可借助安装在已知位置的参考站消除大部分GNSS错误。在高级接收器上应用DGNSS技术时，可以达到亚米级精度。2016年，Android向开发人员开放了原始GNSS测量的访问权限。但是，大多数中低端智能手机仅使用美国国家海洋电子协会（NMEA）协议提供数据。他们不提供原始测量值，因此也不支持DGNSS操作。我们提出了DGNSS基础结构，该基础结构使用参考站的更正来更正智能手机的独立GNSS位置。在基础架构中，考虑到有助于智能手机中独立解决方案的GNSS卫星ID生成位置校正，并且获得的位置等效于直接使用范围域校正的解决方案。为了为大量的智能手机用户提供服务，开发了一种客户端/服务器体系结构来有效地处理大量DGNSS定位请求。在空旷地区进行的所有现场测试中，将拟议的基础设施与地面真实情况进行比较，结果表明，该基础设施的水平定位精度优于2 m。对于下午的测试，准确性的提高可以达到50％以上。该基础结构为需要更高准确性而无需任何硬件修改的应用程序带来了好处。