The SOPAC Refined Model Java Time Series applet displays north, east and up time series for the site(s) of interest. Select the four-character site code and filter type using the input fields or site filtered/unfiltered links. See below for information regarding unfiltered vs. filtered time series.
Due to long applet download times, we recommend that users with low bandwith connections (e.g., dialup accounts) view the static .gif image time series by clicking on the "Non-Java Refined Time Series Plots" link.
If you have trouble downloading the applet, and are not redirected to the java plugins page by the applet, you can obtain the required plugin here. Some Mozilla browsers crash with this version of the plugin; try the prior version.
Help for the Java Time Series applet is available via the "Help" button in the applet. This help dialog describes the functionality of the various buttons and dropdown menus in the applet.
To change sites, use the "Change site" text field in the applet. To layer sites, select a GPS array from the "Layer sites from" dropdown menu. This will open a dialog window that contains a list of sites for that array. Using the change site tools within the applet will provide quicker time series plotting than re-loading the applet from this page via the input fields or site links.
Refined model information
Site coordinates, velocities and time series are created by a SOPAC refined model (Nikolaidis, 2002) that takes into account offsets (co-seismic or otherwise), linear velocity, and annual and semi-annual fluctuations (for stations that have at least two years and one year of data, respectively). For stations that experience post-seismic relaxation, an exponentially decaying term is also estimated. In some cases where a station experiences coseismic and post-seismic deformation, changes in the linear velocity are also estimated. These parameters can be viewed via the refined model terms utility.
Input data provided to the model are the daily processed site positions calculated at SOPAC using the GAMIT and GLOBK software packages. Coordinates from the most recent SOPAC weekly processing run are available, and are generated using data for that week only. Conversely, products from the refined model (e.g., coordinates) are calculated based on the entire timeseries for a site.
All parameters are estimated with full white noise + flicker noise covariances
based on a noise analysis of the GPS position time series. Their uncertainties
can thus be considered realistic estimates, based on our data analysis.
For sites in the western United States, filtered coordinates are available. This includes sites in the BARGN, BARD, EBRY, PANGA, and SCIGN permanent GPS networks, and western U.S. sites in the CORS network.
The regional filtering is carried out in space domain. By stacking the
time series from a group of core sites, a time series containing common noises for the region can be derived, which will then be subtracted from individual time
series to improve positional estimates. Unfiltered time series are also available for these sites. For all other sites, only unfiltered time series are available. No regional filtering is performed for these sites.
Please contact the webmaster if you have any questions.
Reference:
Nikolaidis, R., Observation of Geodetic and Seismic Deformation with the Global Positioning System, Ph.D. Thesis, University of California, San Diego, 2002.
