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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.

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.

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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.