GROOPS是由于奥地利格拉茨大学（TU Graz）、波恩大学等团队学者开发的重力场恢复面向对象程序系统，其由C++ 语言开发（+部分Fortran代码），支持的任务包括地球重力场恢复（GRACE）、GNSS卫星定轨、精密单点定位（PPP）、低轨卫星定轨、局域椭球确定等。
获取地址
论文描述：Mayer-Gürr, T., Behzadpour, S., Eicker, A., Ellmer, M., Koch, B., Krauss, S., Pock, C., Rieser, D., Strasser, S., Suesser-Rechberger, B., Zehentner, N., Kvas, A. (2020). GROOPS: A software toolkit for gravity field recovery and GNSS processing. Earth and Space Science Open Archive, 8. https://doi.org/10.1002/essoar.10505041.1
代码托管：https://github.com/groops-devs/groops
代码许可：GPLv3
文档网站：https://groops-devs.github.io/groops/html/index.html
这个文档写得很好、很详细！对每一步操作、每一个函数的数学原理、输入输出变量、典型设置等都有详细解释。
论文摘要：The Gravity Recovery Object Oriented Programming System (GROOPS) is a software toolkit written in C++ that enables the user to perform core geodetic tasks. Key features of the software include gravity field recovery from satellite and terrestrial data, the determination of satellite orbits from global navigation satellite system (GNSS) measurements, and the computation of GNSS constellations and ground station networks. Next to raw data processing, GROOPS is capable to operate on time series and spatial data to directly analyze and visualize the computed data sets. Most tasks and algorithms are (optionally) parallelized through the Message Passing Interface, thus the software enables a smooth transition from single-CPU desktop computers to large distributed computing environments for resource intensive tasks. For an easy and intuitive setup of complex workflows, GROOPS contains a graphical user interface to create and edit configuration files. The source code of the software is freely available on GitHub (https://github.com/groops-devs/groops) together with documentation, a cookbook with guided examples, and step-by-step installation instructions.
配置和运行
看简单的介绍，由xml文件进行配置，配置文件中标明多个程序（Program）运行流程（和Bernese类似）。文档网站上给出了每一个程序（Program）的详细功能介绍，和地球重力场恢复（GRACE）、GNSS卫星定轨、精密单点定位（PPP）、低轨卫星定轨、局域椭球确定的参考配置文件。
A configuration file consists of a list of [programs] that are executed in sequential order. Each program comes with its own config options and they work independently without any internal communication between programs. Data flow between programs is realized via files. An outputfile of one program can serve as an inputfile for the next program. Most programs are deliberately kept small and focused on a specific task. This modularity combined with the general purpose design of many programs enables the creation of complex workflows with little effort. Including loops and conditions in a config file provides even more flexibility.
Individual programs (and also other optional config elements) can be disabled and are ignored during execution. Mandatory config elements are indicated by a star (*). Empty optional elements are ignored or a meaningful default value is assumed.
部分结果 （来自论文）
