研究机构：
1、Research Group of Astronomy and Geomatics(gAGE), Technical University of Catalonia(UPC),Barcelona,Spain
http://www.gage.upc.edu/drupal6/forum/inospheric-model
2、iGMAS网站
http://124.205.50.178/Home/Index/Index/nav_id/1.html
3、美国GPS官方网站
https://www.gps.gov/systems/gps/space/#generations
4、中国科学院上海天文台
http://202.127.29.4/geodesy/index.html
International Workshop on GNSS Ionosphere (IWGI2018)
http://202.127.29.4/geodesy/iwgi2018/index.html
文献下载：
1、LabXing(Its functions are similar to sci-hub.)
https://www.labxing.com/paper
数据下载：
1、The F10.7,Kp, Dst, Ap,etc indices data are available through ：
http://omniweb.gsfc.nasa.gov/form/dx1.html
https://omniweb.gsfc.nasa.gov/form/dx4.html
The data can be downloaded as a file or list,and plotted as well.
added:
solar data, satellites data, ionosphere data
ftp://ftp.ngdc.noaa.gov/STP
2、CODE GIM Product Overview（GIMs/IONEX/DCBs）
http://aiuws.unibe.ch/ionosphere/#cgim
CODE’s ionosphere products are available via the AIUB anonymous ftp server(ftp://ftp.aiub.unibe.ch/) in the IONosphere map EXchange (IONEX) format and in the ION format of the Bernese GPS Software.
TEC maps：ftp://ftp.aiub.unibe.ch/CODE/
Since June 1, 1998, the final IONEX product is delivered weekly to CDDIS(https://cddis.nasa.gov/), a global data center of the IGS. Examples of both file types containing the most recent GPS-derived GIM information are accessible here
Global Ionosphere Maps Produced by CODE
http://aiuws.unibe.ch/ionosphere/
3、中国地震局GNSS数据产品服务平台
ftp://ftp.cgps.ac.cn/products/
英语网站
1、朗文在线词典
https://www.ldoceonline.com/
2、剑桥词典，集单词查询、翻译、语法于一身
https://dictionary.cambridge.org/
3、基本解释，同根词的变形，同义词对比和区别，反义词，有例句；
http://www.thefreedictionary.com/
科研工具：
1、PDF在线转换：
http://www.pdfdo.com/
2、ProcessOn支持流程图、思维导图、原型图、UML、网络拓扑图等，可部分代替visio功能
https://www.processon.com/
3、免费下载英文电子书（Library Genesis）
http://gen.lib.rus.ec/
开源社区：
1、The GPS Toolbox
This site is affiliated with the GPS Toolbox column published quarterly in the journal: GPS Solutions. The main purpose of this site is to provide a means for distributing the source code and algorithms discussed in the GPS Toolbox column. By providing this source code, we hope to encourage a dialog among GNSS programmers about source code and algorithms used for a variety of applications.
https://www.ngs.noaa.gov/gps-toolbox/
2、verysource（source code download）
http://en.verysource.com/
3、Per Christian Hansen（大神）自己编写正则化工具箱，里面有很多解函数可以直接调用，包括3D CT, tomography reconsruction
http://www.imm.dtu.dk/~pcha/