NASA will be performing network maintenance on Wednesday, November 20, 2024, between 11:00 AM EST and 1:00 PM EST (16:00 to 18:00 UTC). There will be two periods of about five minutes of disruption. During these peroids, the ILRS website will be unavailable during the outages. If you experience problems outside this window, contact support-cddis@nasa.gov.

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Data Center Operations

The ILRS utilizes previously developed data flow paths to provide satellite and lunar laser ranging normal point (NP) and fullrate data and predictions to the user community. At a minimum, laser stations forward their data to operations/data centers on a daily basis where they are merged into files by day and satellite for transmission to and archive at the global data centers. Prediction Centers email their predictions to their select set of stations and the global data centers. Currently, the two ILRS global data centers make their data holdings available in different directory and file structures. These centers exchange their recently-delivered NP data at least once per day to ensure that their holdings are equalized and that users can continue to reliably access NP data should one center be unavailable.

In August 2019, the ILRS Operations Centers (OCs) at EDC and NASA updated their data screening process in order to coordinate data quality control (QC) and provide feedback on data issues to the stations. Incoming data are screened and characterized as:

  • "errors" if they will adversely impact the quality of the data and the derived data products (e.g., invalid date, invalid satellite, erroneous calibration, etc.)
  • "warnings" if the impact on the quality of the data is minor, or if there are format errors that make processing or QC evaluation more difficult.

Both ILRS Operations Centers now use the same criteria for screening incoming data. Data that are marked as having errors will not be submitted to the ILRS Data Centers at EDC and CDDIS. Data marked as having warnings will be submitted. The OCs will forward the diagnostics to the stations on a routine basis for necessary action. Stations should address the error issues immediately.

A list of the new data QC to be implemented at the OCs (categorized as errors or warnings) is attached and can be found at:

https://ilrs.gsfc.nasa.gov/network/site_procedures/data_screening_procedure.html