SCIGN Analysis

Jet Propulsion Laboratory

Last updated on Wed Oct 13 22:00:08 PDT 2004

Number of hits: 258

The Southern California Integrated GPS Network (SCIGN) is a collaborative project to install 250 permanent, continuously recording Global Positioning System (GPS) receivers in and around the Los Angeles basin to provide accurate deformation information that will improve our estimates of earthquake hazards. Major participants in SCIGN include NASA/JPL, The United States Geological Survey (USGS), and The University of California San Diego, operating under the umbrella of the Southern California Earthquake Center (SCEC). Chief sponsors of the SCIGN network are the W. M. Keck Foundation, The National Science Foundation, NASA, and the USGS. Currently, SCIGN is in the process of identifying and selecting candidate sites for installation based on the DOTS3 map.

(For a more detailed map of the station distribution click here)

Current Status of SCIGN

Information is available on the site status, data quality (engineering data) from analyses at JPL using GIPSY, and time series of station coordinates.

Status

Each station is assigned a composite score based on data quantity, quality, and latency. Select documentation for detailed information on how these are computed. Green indicates a composite score of 8 or more, and red 5 or less. Sites with intermediate values are indicated with yellow. (Blue indicates that, although data were available at one or more Global Data Centers, they were not successfully processed at JPL in time for the report.) The score reflects a moving 7-day average.

Engineering

Plots and statistics are available for the time series of station performance for each day analyzed by the JPL quick look process. These statistics include for daily mean values for the phase residuals (mm), pseudorange residuals (cm), clock (ns), number of epochs processed, number of phase breaks detected, the number of days processed, and days since the last day processed. Tables are available for the global network and for SCIGN.

Time Series

Given 24 hours of GPS data the latitude, longitude, and height of each receiver can be computed to within a few mm. Time series graphically illustrate the evolution of receiver positions from day to day. A global reference frame called ITRF96 is used for all time series. Each plot includes the estimated positions with error bars, the best fit line, and the residual scatter which is an indication of the daily measurement precision. The motion of each site is due to a combination of inter-seismic, co-seismic, and post-seismic effects. Time series are also available for all global network site s.

Educational Page

To learn more about educational activities related to SCIGN, please visit SCEC's SCIGN Educational Module at http://scign.jpl.nasa.gov/learn . This interactive, on-line module presents background text and activities related to plate tectonics, earthquakes, GPS, and space technology at work. Real SCIGN data is used in the activities.

To get information on a station either click on the map symbol or select from the list box

Select a station	Click on the station

U.S. Government sponsorship acknowledged under NAS7-1260

For more information contact the
The SCIGN Analysis Team of the
Satellite Geodesy and Geodynamics Group