Entry Date:
February 18, 2010

Global Positioning System (GPS)


Ionospheric scientists use GPS observables to measure properties of the electron density such as the total electron content (TEC). The TEC is a measure of the total number of electrons that would be contained in a cylinder that extends up vertically above a given point on the earth all the way through the ionosphere. By incorporating data from multiple receivers (greater than 2000) distributed over the globe, scientists are able to generate wide-ranging spatial maps of the TEC. The deployment of these receivers is rapidly increasing and some areas already have very dense networks (e.g. Japan, North America, and Europe). Two dimensional TEC maps have revealed dramatic insights into storm time magnetosphere-ionosphere (M-I) coupling at sub-auroral latitudes [Foster et al. [2002], Coster et al., [2003]). MIT Haystack has automated the process of downloading and processing GPS data to produce globally gridded TEC data. The algorithms used in the MIT Automated Processing of GPS (MAPGPS) software package have been described by [Rideout and Coster, 2006]. Processed TEC data is available to the entire scientific community via MIT Haystack's Madrigal database.