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News in 2017

The purpose of this page of the CDDIS web site is to post new items, activities, data sets, etc. of interest to the CDDIS user community. Users should also consult the meetings page to view a list of upcoming meetings and events of interest to the space geodesy community.

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CDDIS Computer System Outage
(15 November 2017)

CDDIS must undergo an unplanned outage on 16-Nov-2017 from 14:00-18:00 EST (19:00–22:00 UTC) to replace critical system hardware. All CDDIS services (archive/website access, file upload) will not be accessible; however, the real-time CDDIS GNSS caster will remain operational. We expect that the system outage will not require the full 4 hours but have allocated time to address any unforeseen issues.

We apologize for any inconvenience these outages may cause the user community.

GRACE satellites

GRACE mission ends science operations
(27 October 2017)

After more than 15 productive years in orbit, the U.S./German GRACE (Gravity Recovery and Climate Experiment) satellite mission has ended science operations. During their mission, the twin GRACE satellites have provided unprecedented insights into how our planet is changing by tracking the continuous movement of liquid water, ice and the solid Earth.


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Interruptions in network connectivity to CDDIS
(27 October 2017)

The CDDIS network will undergo maintenance on Tuesday, October 31, 2017 between 15:00 - 19:00 UTC. There may be extended interruptions in connectivity to the CDDIS during this maintenance period but we expect only short 5-10 minute outages during the timeframe.

We apologize for any inconvenience these outages may cause the user community.

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NASA Earth Science Data and Services Survey for 2017
(15 September 2017)

Dear Colleagues,

Recently, some of you may have received an email from the CFI Group on behalf of NASA. This message asked you to complete a survey for users of NASA Earth science data and services, which includes the Crustal Dynamics Data Information System (CDDIS). The CDDIS is one of twelve NASA Earth Observing System Data and Information System (EOSDIS) science data centers evaluated by this survey. The purpose of this survey is to help NASA and the DAACs assess customer satisfaction and improve future services. Suggestions from past surveys have been implemented to improve the tools and services offered by the CDDIS.

Please participate! Your feedback affects our future performance and helps to identify science needs. You will be able to take the survey for each DAAC you use. This is your opportunity to influence the priorities of the DAACs, including CDDIS. Thank you in advance to all of you who are willing to spend a few minutes to complete the survey.

If you did not receive a survey and wish to complete one or know of someone who uses CDDIS and/or EOSDIS data and services who did not receive a survey, please contact


The American Customer Satisfaction Index (ACSI) is the only national cross-industry measure of customer satisfaction in the United States. NASA commissioned the CFI Group, an independent research and consulting organization, to conduct a brief survey to rate the products and services NASA currently provides from NASA's EOSDIS data centers. Please consider responding to this survey; your input will help us to better serve our user community.

Presentations of these results given to NASA Earth science are available at:


Thank you in advance to all of you who are willing to spend a few minutes to complete the survey.

ESIP logo

CDDIS has been accepted as an Earth Science Information Partners (ESIP) Type 1 member
(04 August 2017)

CDDIS is pleased to report that it has been accepted as an Earth Science Information Partners (ESIP) Type 1 member, joining over 180 partner organizations that include many of the other NASA DAACs. ESIP is a non-profit, volunteer and community-driven organization that advances the use of Earth science data through meetings and virtual collaborations around topics such as data stewardship, information technology and interoperability, and application areas like disaster response, climate, energy and agriculture. Type 1 members are distributors of satellite and ground-based data sets and the products derived from these data.

Cov er of the Journal of Geodesy

Printed version of the Journal of Geodesy Special Issue on VLBI now available
(21 June 2017)

The printed version of the Journal of Geodesy Special Issue on VLBI: Journal of Geodesy, Volume 91, Issue 7, July 2017, is now available at https://link.springer.com/journal/190/91/7/page/1. This volume includes a Preface and 14 scientific articles devoted to various aspects of the VLBI theory, methodology and data analysis.

Satellite laser ranging at GSFC.

Innovation column in GPS World discusses importance of laser ranging to GNSS satellites
(25 May 2017)

In the May 2017 Innovation column of GPS World, author Urs Hugentobler discusses the importance of laser ranging to GNSS satellites for improvement in modeling the orbits of these satellites. Better GNSS satellite orbits result in better receiver position accuracies, which are required to improve monitoring of Earth processes.

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Changes to quarantine data directories on CDDIS
(25 April 2017)

As of today, 25-Apr-2017, the CDDIS has changed its directory structure for quarantined SLR data. The CDDIS recently implemented changes to our incoming SLR data processing and archiving procedures. These changes required that we now archive quarantined SLR data (both normal points and full-rate) in subdirectories by station number, rather than subdirectories by site name; these directories are located at:



Older data will be transitioned to this new structure in the near future. EDC has used this directory convention for its quarantined data files. Please contact the CDDIS manager if you have any questions or problems with the new CDDIS archive structure.

NRK TV (Norway) features the need for a precise Terrestrial Reference Frame, and discusses role of NASA and the Space Geodesy Program

NRK TV (Norway) features the need for a precise Terrestrial Reference Frame, and discusses role of NASA and the Space Geodesy Program
(14 April 2017)

NRK TV in Norway has published a video feature (in Norwegian) discussing the importance,and challenges of global cooperation in making precise measurements to support the maintenance of an international terrestrial reference frame necessary for natural hazard and global change studies. The video also discusses the future plans for cooperation with NASA in the construction of the geodetic station in Ny Alesund. The video features interviews (in English) with SGP Manager Stephen Merkowitz (Code 61A @ NASA GSFC; time index 5:26, 8:45, 10:20) and colleagues Hayo Hase (AGGO, La Plata Argentina ; time index 11:14 20:07) Ludwig Combrinck (HartRAO, South Africa; time index 6:24, 17:24); Per Erik Opseth, Laila Lovhoiden, Gary Johnston (Geoscience Australia, time index 20:53, 23:05), and others, as well as a visit to NASA GSFC and GGAO. The full URL for the television program is: https://tv.nrk.no/program/KOID75001017/jakten-paa-den-eksakte-posisjon.

NASA logo

Upcoming maintenance on CDDIS and ILRS email exploders
(14 April 2017)

The NASA system used for CDDIS and ILRS email exploders will be undergoing maintenance from 13:00 - 17:00 UTC on April 23.

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ILRS survey of user tracking needs
(21 March 2017)

Many stations in the ILRS network are nearly saturated in their tracking schedule. The ILRS is presently assessing its tracking needs to try to maximize its utility. We recently sent out an email to various ILRS users and groups to ask for user needs. If you want your needs to be considered, and did not receive an email invitation, please send an email to Erricos Pavlis (epavlis @ umbc.edu). Once we compile the results, the ILRS plans to make revisions to its tracking list based on users needs. Therefore, user input is critical. The survey should not take you more than 5-10 minutes to complete, depending on your level of involvement with SLR data. Thank you for supporting the ILRS!

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RINEX V3 BRDC file now available
(28 February 2017)

Using software supplied by the IGS Infrastructure Committee, the CDDIS is now generating a combined, concatenated broadcast ephemeris file containing unique multi-GNSS navigation messages in RINEX V3 format. The files, starting operationally in late February 2017, are named BRDC00IGS_R_yyyyddd0000_01D_MM.rnx.gz and are available on the CDDIS in the yearly BRDC directory (ftp://cddis.nasa.gov/gnss/data/daily/YYYY/brdc) and in the daily "p" subdirectories (ftp://cddis.nasa.gov/gnss/data/daily/YYYY/DDD/YYp). The file is created using the individual station "01D_MN.rnx" RINEX 3 broadcast ephemeris files using navigation messages from each satellite constellation and removes duplicate entries. The CDDIS will create older RINEX V3 BRDC files going back to 01/2016 in the near future.