To meet the demands of precise orbit and clock determination, high-precision positioning, and navigation applications, a software called GREAT (GNSS + Research, Application and Teaching) was designed and developed at Wuhan University. As one important module in the GREAT software, GREAT-UPD was developed for multi-GNSS and multi-frequency uncalibrated phase delay (UPD) estimation. It can provide extra-wide-lane (EWL), wide-lane (WL), and narrow-lane (NL) UPDs for GPS, GLONASS, Galileo and BDS (GREC) satellites for precise point positioning (PPP) ambiguity resolution (AR) in a multi-GNSS and multi-frequency environment. The open-source GREAT-UPD software is written in C + + 11 language following object-oriented principles and can be compiled and run on several popular operating systems, such as Windows, Linux, and Macintosh. Observations from 222 stations spanning days from DOY 091 to 120 were used to conduct multi-GNSS and multi-frequency UPD estimation and PPP AR. Results indicate that GREAT-UPD can generate stable and reliable UPD products with multi-GNSS and multi-frequency observations. After applying the UPD corrections, the multi-frequency GREC PPP AR was achieved with the averaged time to first fix of 9.0 min. The software package can be obtained at https://geodesy.noaa.gov/gps-toolbox, including the source code, user manual, batch processing scripts, example data, and some auxiliary tools.

为了满足精确的轨道和时钟确定，高精度定位和导航应用的需求，武汉大学设计并开发了一款名为GREAT（GNSS +研究，应用和教学）的软件。作为GREAT软件中的一个重要模块，GREAT-UPD被开发用于多GNSS和多频率未校准相位延迟（UPD）估计。它可以为GPS，GLONASS，伽利略和BDS（GREC）卫星提供超宽车道（EWL），宽车道（WL）和窄车道（NL）UPD，以实现精确的点定位（PPP）模糊度解析（AR） ）在多GNSS和多频率环境中进行。开源的GREAT-UPD软件遵循面向对象的原则，以C ++ 11语言编写，可以在多种流行的操作系统（例如Windows，Linux和Macintosh）上进行编译和运行。使用从DOY 091到120天的222个站点的观测数据进行多GNSS和多频率UPD估计以及PPP AR。结果表明，GREAT-UPD可以通过多GNSS和多频观测生成稳定可靠的UPD产品。应用UPD校正后，多频GREC PPP AR的首次定位平均时间为9.0分钟。可以从https://geodesy.noaa.gov/gps-toolbox获得该软件包，包括源代码，用户手册，批处理脚本，示例数据和一些辅助工具。应用UPD校正后，多频GREC PPP AR的首次定位平均时间为9.0分钟。可以从https://geodesy.noaa.gov/gps-toolbox获得该软件包，包括源代码，用户手册，批处理脚本，示例数据和一些辅助工具。应用UPD校正后，多频GREC PPP AR的首次定位平均时间为9.0分钟。可以从https://geodesy.noaa.gov/gps-toolbox获得该软件包，包括源代码，用户手册，批处理脚本，示例数据和一些辅助工具。