US Government security requirements no longer permit CDDIS to offer data via traditional unencrypted anonumous ftp; this service was discontinued on October 31, 2020. All data are still available, however access must be via HTTPS or ftp-ssl.

Instructions with examples and our FAQ can be found at: https://cddis.nasa.gov/Data_and_Derived_Products/CDDIS_Archive_Access.html.

If you still have difficulty after reading and attempting the examples on that page, please contact us at support-cddis@earthdata.nasa.gov.

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Learn about Techniques
15 November 2020

Precise Orbit Determination (POD) is a geodetic technique that enables knowing the exact position of a satellite above a stable reference point on Earth. Determining the exact position of the satellite when an observation is acquired is crucial in measuring sea level height. As noted by Dr. Frank Lemoine, a geodesist with NASA's Space Geodesy Project and a member of NASA's Ocean Surface Topography science team, "If you don’t do POD right, you're not going to get any sea level results."

Read the full article on nasa.gov...


October 2020

Registration for the virtual tours is now open. Attendance for each session will be limited to 250 connections and will be available on a first come, first served basis. We encourage group attendance where possible; only one person is required to register for the group. Interested parties can register at:

https://cddis.nasa.gov/ILRS_Virtual_World_Tour_2020/Registration/

Attendees are required to register for each session they plan to attend. There is no fee for registering and attending any of the tours. Registration will be closed on October 26, 2020.


25 September 2020

In place of the planned Workshop this November, the ILRS wanted to take the opportunity to try something different and look in detail at a selection of stations in the global network. The online 'Virtual World Tour', to be held November 2-6, 2020, will visit 5 stations in 5 days, stopping at:

  • Graz, Austria
  • Greenbelt MD, USA
  • Simosato, Japan
  • Yarragadee, Australia
  • Zimmerwald, Switzerland

Each two-hour session will consist of an introductory presentation about the station followed by a tour of the site highlighting instrumentation, software, safety, automation, operations, as well as current issues and future plans. These tours will include a mixture of pre-recorded and live presentations with an opportunity for questions.

More information about the workshop can be found on the website:

https://cddis.nasa.gov/ILRS_Virtual_World_Tour_2020/index.html

and in the second circular.


Weekly GNSS data holdings (daily, hourly, high-rate)

Weekly SLR normal point pass segment totals (by satellite, LAGEOS and ETALON only)

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