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CDDIS Archive Explorer FAQ
  1. What is the Archive Explorer?
    The Archive Explorer is an application developed for searching CDDIS data holdings. Users can specify temporal and/or spatial parameters to refine their query.
  2. How do I use the Archive Explorer?

    First, select the data type. Queries for GNSS, SLR, and DORIS data holdings are available now; queries for VLBI data holdings will be available soon. Once the data type is selected, additional query options will appear. For GNSS, users can specify a data rate (daily/hourly/high-rate); for SLR and DORIS, users can select a satellite from a drop down list. Next, optionally specify temporal and/or spatial parameters to refine the query. Temporal parameters can be directly entered or chosen with the calendar provided. Spatial parameters can be specified by zooming in (using the '+' and '–' buttons in the upper left of the map) and panning the map until the region of interest fills the map space or by using a bounding box (<Shift>-click on the map). The 'Reset' button on the map will display the map in the full world view if the user has zoomed in.

    Once all desired parameters have been entered, click 'Find Sites' to view the results. The map will be populated with site locations and a list of these sites will appear below the map in the Search Results window; the total number of sites satisfying the input parameters will be shown in the Search Results window header. Click on any site location (on the map or in the Search Results window) to see the site highlighted in the Search Results window. A 'View' button will display information about the selected site, including the site log (if available) and site photograph(s) in the Site Details box.

    The 'Start Over' button is available to reset the query and enter new values. Using the 'Start Over' button is required when any new values for data type or temporal/spatial parameters are desired.

  3. Do I have to enter date values or map locations?
    No. The only required entry is data type. The temporal and spatial values are optional.
  4. What is the input format for dates?
    Start and end dates must be entered in the form 'mm/dd/yyyy'.
  5. How do I specify spatial parameters?
    Users can view results for the entire world or select a specific area. To specify an area, enter minimum and maximum latitude and longitude values. Alternatively, hold down the <Shift> key, click on the map, and draw a box around the area of interest. Clicking on the map and dragging will move the zoom area to another location of the map. Users can also zoom in and pan the map until the desired region fills the map space.
  6. What is the blue diamond on the lower right corner of the map?
    The application uses the open source library OpenLayers for displaying map data. The blue diamond is the OpenLayers icon; clicking on the icon will allow the user to learn more about OpenLayers.
  7. Can I save the resulting table from my above defined query?
    Not at this time. The next version of the Archive Explorer will allow users to save the results in a comma separated value (CSV) file.
  8. Now that I have a list of sites and dates I’m interested in, how can I get the data?
    All data listed in the Search Results window are available in the CDDIS archive through anonymous ftp. Users can consult the CDDIS website, particularly http://cddis.gsfc.nasa.gov/Data_and_Derived_Products/index.html, to learn more about the archive structure and how to download data of interest.
  9. Are there any browser compatibility issues?
    The only issue some users have noticed is with Internet Explorer 9 on Windows. The application has been tested successfully on Windows using IE 10 and Firefox.