Survey-Mode GPS Data at the SCEC Data Center

The SCEC Data Center archive of GPS data contains data from "survey-mode" precise GPS measurements made in Southern California by various universities, Federal organizations (notably the US Geological Survey and the National Geodetic Survey), the California Department of Transportation, and Southern California counties, cities, and water districts.

Current Status

At this time (July 2006) we have archived nearly all the datasets (that we know of) relevant to monitoring crustal motion in southern Alta California and northern Baja California from 1986 through 2005. For all files in the archive, all pertinent information from the field logsheets is included in the comment section of the RINEX header, and all header information has been checked against the original field logs.

A set of maps of GPS stations has been produced to help with planning of future observations, by showing where past ones have been made (the current versions are old and will be updated soon).

Data Archive Structure

The GPS data archive consists of several parts: raw GPS data, RINEX files, indices to the RINEX files, log sheets, and site descriptions.

Rinex files

There are two categories of RINEX files. Most (about 95%) of the files have been "associated" with a monument in the site index; when this is done, the monument location (good to 1 m) is put in the RINEX header. These files are organized by year and day and are accessible from the associated data archive . Any data for which we have not yet made this association (about 5% of the total, mostly single occupations of marks) are located in the unassociated data archive which is organized by year, data type (always RINEX) and day.

Indices

In addition to the site index (see below), there is a summary file which gives a list of all RINEX files, in chronological order (the first field is an obvious modification of the RINEX name; the second field gives the location of the logsheet, in our local collection). There is also an occupation list which gives, for each site, the names of the RINEX files associated with it.

Raw GPS Data

Raw GPS files are also archived at the SCEC Data Center, however, these are not generally available to users (contact us directly for access). We do not have raw files for all data. For some pre-1990 data we have raw data but not (yet) RINEX.

Log Sheets

Logsheets are kept in notebooks at our office at UCSD. As we archive data we use these to ensure that the antenna height is the RINEX standard; comments from the logsheet are also included in the RINEX header. We can provide copies (mail or fax) of logsheets, but this should rarely be necessary.

Site Lists and Site Descriptions

An ASCII index of monuments used for GPS measurements (the "site index") is available here and a description of its contents can be found in .JPG or .PS formats: .PS, .JPG_1, .JPG_2 The map of these sites shows which ones have an NGS Permanent ID included in the site index; for these, a complete station description can be gotten from the NGS Web page. We have descriptions for some sites, but by no means all.

Continuous GPS Data

Data from the Southern California Continuous GPS Network (SCIGN) and other continuous stations are archived at the Scripps data center; see also the USGS and JPL SCIGN pages.

Southern California survey-mode GPS data contact:

Duncan Agnew (dagnew at ucsd dot edu)

SCECDATA CENTER HOME PAGE