The GNSS data collected at NCN stations are made available to the public by NGS in Receiver INdependent EXchange (RINEX) format. Most data are available within 1 hour (60 minutes) from when they were recorded at the remote site, and a few sites have a delay of 24 hours (1440 minutes).

• Hourly files are only kept for 2 days.
• Daily files are kept permanently, available in 2 formats:
  • GNU gzip-compressed of data in the Hatanaka-compression RINEX format (*.yyd.gz)
  • GNU gzip-compressed of data in RINEX format (*.yyo.gz)
  However,
  • After 30 days, daily files are decimated to 30s sampling rate.
  • After 6 months, only gzip-compressed files of daily data in the Hatanaka-compression RINEX format (*.yyd.gz) are provided.
• For RINEX v2 data, NGS utilizes UNAVCO's TEQC software on incoming data for quality checking purposes. Daily data quality information generated by TEQC -qc are stored with daily data files.
• Navigation data files are available only for sites that NGS submits to the IGS network.
• Meteorological data files are available only for sites with independent meteorological sensors.

Access Methods:

• Daily RINEX observation data can be found at:
  • NCN on AWS: https://noaa-cors-pds.s3.amazonaws.com/rinex/YYYY/DDD/ssss/File-Name
    For more information about this service, visit NOAA Open Data Dissemination (NODD) program.
  • NGS server: https://geodesy.noaa.gov/corsdata/rinex/YYYY/DDD/ssss/File-Name
  • NCEI's CLASS: https://www.avl.class.noaa.gov/saa/products/search?datatype_family=CORS
    The National Centers for Environmental Information (NCEI) via NOAA's Comprehensive Large Array-data Stewardship System (CLASS) provides original at-sampling rate RINEX data from 2004 to present (30-day delay). While large data orders may take a few days to fulfill, small data requests are nominally fulfilled within the day.
• Partial-day/Joining-day/Decimating RINEX data can be requested from NGS's User Friendly CORS (UFCORS): https://geodesy.noaa.gov/UFCORS/

File Name	Description	Frequency
ssssDDD0.YYd.gz	GNU gzip-compressed daily Hatanaka-compression RINEX v2	Daily
ssssDDD0.YYo.gz	GNU gzip-compressed daily RINEX v2	Daily
ssssDDDh.YYd.gz	GNU gzip-compressed hourly Hatanaka-compression RINEX v2	Hourly
ssssDDDh.YYo.gz	GNU gzip-compressed hourly RINEX v2	Hourly
ssssDDD0.YYS	Daily TEQC Summary file for RINEX v2	Daily

Station log files contain all the historical equipment (receiver/antenna) used at that station, approximate location, owner and operating agency, etc.

We strongly recommend that the the position/coordinates listed in the log file like that in the RINEX header files should be considered APPROXIMATE. When a user downloads data, they should at the same time download the published NGS coordinate (position and velocity) file for that station.

A station log can be found at:

• NOAA-NCN bucket: https://noaa-cors-pds.s3.amazonaws.com/station_log/ssss.log.txt
  For more information about this service, visit NCN on the Registry of Open Data on AWS
• NGS server: https://geodesy.noaa.gov/corsdata/station_log/ssss.log.txt
• NCEI's CLASS: https://www.avl.class.noaa.gov/saa/products/search?datatype_family=CORS
  The National Centers for Environmental Information (NCEI) via NOAA's Comprehensive Large Array-data Stewardship System (CLASS) provides original at-sampling rate RINEX data from 2004 to present (30-day delay). While large data orders may take a few days to fulfill, small data requests are nominally fulfilled within the day.

In July 2019, NGS has published MYCS2!

Previous published coordinates and velocities of NCN stations can be found here

On January 29, 2017 (GPS week 1934), the International GNSS Service (IGS) released the new coordinates and corresponding antenna calibrations in the IGS realization of the International Terrestrial Reference Frame 2014 (ITRF2014). As part of this transition, products in the IGS08 frame are no longer updated. Instead, all the updates will be in the ITRF2014 frame.

Although NGS did not participate in the 2nd IGS reprocessing campaign, we have completed the reprocessing of the NCN and IGS Network stations. The newly reprocessed solution, called the Multi-Year CORS Solution 2 (MYCS2), is aligned to the ITRF2014 frame. MYCS2 supersedes the previous reference frame and realization, which was released in 2011 under the name MYCS1. The final alignment of our No-Net-Rotation (NNR) SINEX files to ITRF2014 used 496 solutions from 194 ITRF2014 stations, not including any of the 26 IGS stations with post-seismic behavior. The MYCS2 generally implemented the International Earth Rotation Service (IERS) 2010 conventions.

For more information, please visit: Adoption of ITRF2014/IGS14 and the Multi-Year CORS Solution 2 (MYCS2)

On May 2020, NGS has adopted the IGb14 frame and updated the published coordinates and velocities of 49 globally dispersed IGS stations used in NGS's data processing. For more information, please visit: Transitioning from IGS14 to IGb14

MYCS2 published coordinates of each NCN station can be found at:

• NOAA-NCN bucket: https://noaa-cors-pds.s3.amazonaws.com/coord/coord_14/ssss_14.coord.txt
  For more information about this service, visit NCN on the Registry of Open Data on AWS
• NGS server: https://geodesy.noaa.gov/corsdata/coord/coord_14/ssss_14.coord.txt

MYCS2 published coordinates of NCN stations by reference frames can be found at:

• NOAA-NCN bucket: https://noaa-cors-pds.s3.amazonaws.com/coord/coord_14/File-name
  For more information about this service, visit NCN on the Registry of Open Data on AWS
• NGS server: https://geodesy.noaa.gov/corsdata/coord/coord_14/File-name

Coordinate files are updated as needed per the following policy.

All published coordinates and velocities are given for the Antenna Reference Point (ARP).

File Name	Description
All NCN stations - ITRF2014
itrf2014_xyz.comp.txt	Computed ITRF ECEF XYZ coordinates and velocities
itrf2014_geo.comp.txt	Computed ITRF Geodetic coordinates and velocities
itrf2014_xyz.htdp.txt	HTDP Modeled ITRF ECEF XYZ coordinates and velocities
itrf2014_geo.htdp.txt	HTDP Modeled ITRF Geodetic coordinates and velocities
NCN stations in CONUS, Alaska and the Caribbean - NAD83(2011)
nad83_2011_xyz.comp.txt	Computed NAD83(2011) ECEF XYZ coordinates and velocities
nad83_2011_geo.comp.txt	Computed NAD83(2011) Geodetic coordinates and velocities
nad83_2011_xyz.htdp.txt	HTDP Modeled NAD83(2011) ECEF XYZ coordinates and velocities
nad83_2011_geo.htdp.txt	HTDP Modeled NAD83(2011) Geodetic coordinates and velocities
NCN stations in Hawaii, American Samoa, and the Marshall Islands - NAD83(PA11)
nad83_pa11_xyz.comp.txt	Computed NAD83(PA11) ECEF XYZ coordinates and velocities
nad83_pa11_geo.comp.txt	Computed NAD83(PA11) Geodetic coordinates and velocities
nad83_pa11_xyz.htdp.txt	HTDP Modeled NAD83(PA11) ECEF XYZ coordinates and velocities
nad83_pa11_geo.htdp.txt	HTDP Modeled NAD83(PA11) Geodetic coordinates and velocities
NCN stations in Guam, Palau, and the Commonwealth of the Northern Mariana Islands - NAD83(MA11)
nad83_ma11_xyz.comp.txt	Computed NAD83(MA11) ECEF XYZ coordinates and velocities
nad83_ma11_geo.comp.txt	Computed NAD83(MA11) Geodetic coordinates and velocities
nad83_ma11_xyz.htdp.txt	HTDP Modeled NAD83(MA11) ECEF XYZ coordinates and velocities
nad83_ma11_geo.htdp.txt	HTDP Modeled NAD83(MA11) Geodetic coordinates and velocities

Previous published coordinates and velocities of NCN stations can be found at:

• NOAA-NCN bucket: https://noaa-cors-pds.s3.amazonaws.com/coord/coord_YY/
  For more information about this service, visit NCN on the Registry of Open Data on AWS
• NGS server: https://geodesy.noaa.gov/corsdata/coord/coord_YY/

• Short-term plots show the repeatibility of a site for the last 90-days with respect to the current published position, corrected for the effect of the published velocity. These plots are updated daily.

  Short-term plots of NCN stations can be found at:

  • NOAA-NCN bucket: https://noaa-cors-pds.s3.amazonaws.com/Plots/ssss_YY.short.png
    For more information about this service, visit NCN on the Registry of Open Data on AWS
  • NGS server: https://geodesy.noaa.gov/corsdata/Plots/ssss_YY.short.png

• Long-term plots show the show weekly residual positions with respect to the current published coordinates from our stacked solution. Newer sites may not have a long-term plot if they were added after January 2017. Long-term plots were last updated in September 2019.

  Long-term plots of NCN stations can be found at:

  • NOAA-NCN bucket: https://noaa-cors-pds.s3.amazonaws.com/Plots/Longterm/ssss_YY.long.png
    For more information about this service, visit NCN on the Registry of Open Data on AWS
  • NGS server: https://geodesy.noaa.gov/corsdata/Plots/Longterm/ssss_YY.long.png

• Daily Broadcast Ephemeris

  • Daily GPS Broadcast Ephemeris data can be found at:

    • NOAA-NCN bucket: https://noaa-cors-pds.s3.amazonaws.com/rinex/YYYY/DDD/brdcDDD0.YYn.gz
      For more information about this service, visit NCN on the Registry of Open Data on AWS
    • NGS server: https://geodesy.noaa.gov/corsdata/rinex/YYYY/DDD/brdcDDD0.YYn.gz
  
  

  • Daily GLONASS-only Broadcast Ephemeris data can be found at:

    • NOAA-NCN bucket: https://noaa-cors-pds.s3.amazonaws.com/rinex/YYYY/DDD/brdcDDD0.YYg.gz
      For more information about this service, visit NCN on the Registry of Open Data on AWS
    • NGS server: https://geodesy.noaa.gov/corsdata/rinex/YYYY/DDD/brdcDDD0.YYg.gz
  
  

• GNSS Orbit

  Since the early 1990s, NGS has contributed to enabling GPS/GNSS access to the national spatial reference system by computing high-accuracy GPS orbits. This work has been done together with and as a component of the International GNSS Service (IGS), which coordinates the collection of GNSS tracking data from a global network of reference stations.

  For more information about GNSS orbit data, please visit: IGS's Precise Orbits page.

  Beginning November 27, 2022 we will be providing the SP3 orbit files following the new IGS v1.0 naming convention (see http://acc.igs.org/repro3/Long_Product_Filenames_v1.0.pdf for more information). We will also supply .SP3 files in the existing name format for the time being.

  • Daily final and rapid GNSS Orbit data can be found at:

    • NOAA-NCN bucket: https://noaa-cors-pds.s3.amazonaws.com/rinex/YYYY/DDD/AAAWWWWWD.sp3.gz
      For more information about this service, visit NCN on the Registry of Open Data on AWS
    • NGS server: https://geodesy.noaa.gov/corsdata/rinex/YYYY/DDD/AAAWWWWWD.sp3.gz
    • (SP3 in long filename convention for testing purpose, available from 2022:286) NGS server: https://geodesy.noaa.gov/corsdata/rinex/YYYY/DDD/IGSVPPPTTT_YYYYDDD0000_01D_15M_ORB.SP3.gz
  
  

  • Hourly ultra-rapid GNSS Orbit data (4 files per day) can be found at:

    • NOAA-NCN bucket: https://noaa-cors-pds.s3.amazonaws.com/rinex/YYYY/DDD/AAAWWWWWD_HH.sp3.gz
      For more information about this service, visit NCN on the Registry of Open Data on AWS
    • NGS server: https://geodesy.noaa.gov/corsdata/rinex/YYYY/DDD/AAAWWWWWD_HH.sp3.gz
    • (SP3 in long filename convention for testing purpose, available from 2022:315) NGS server: https://geodesy.noaa.gov/corsdata/rinex/YYYY/DDD/IGSVPPPTTT_YYYYDDDHH00_02D_15M_ORB.SP3.gz

• Sortable list of NCN stations and most current information available at: https://geodesy.noaa.gov/CORS/sort_sites.shtml
  This file is updated daily.

• Historical and current equipment information of all NCN stations, except stations that are considered IGS stations, can be downloaded from:

  • NOAA-NCN bucket: https://noaa-cors-pds.s3.amazonaws.com/station_log/cumulative.station.info.cors
    For more information about this service, visit NCN on the Registry of Open Data on AWS
  • NGS server: https://geodesy.noaa.gov/corsdata/station_log/cumulative.station.info.cors

  This file is based on the master list used by NGS to process data to compute coordinates. This file is updated daily.