Project News

  • GGIM logoSeventh Session of the United Nations Committee of Experts on Global Geospatial Information Management (UN-GGIM) was held on August 2-4, 2017.

    Seventh Session of the United Nations Committee of Experts on Global Geospatial Information Management (UN-GGIM) was held on August 2-4, 2017 at the United Nations Headquarters in New York, preceded by a number of related side events on July 31 through August 1, 2017. The meetings brought together senior officials and executives from national geospatial information and statistical authorities within Member States, and international geospatial experts from across the globe. An important outcome of this session was the establishment of a Subcommittee on Geodesy to provide stability and longer-term planning for the Global Geodetic Reference Frame (GGRF). Participating from NASA’s Space Geodesy Program were: Benjamin Phillips (NASA/HQ), Stephen Merkowitz (NASA/GSFC), and Allison Craddock (NASA/JPL) as US Delegates, and Michael Pearlman (Smithsonian Astrophysical Observatory) as a representative of the International Association of Geodesy.

  • Karen Feldstein, NASA Deputy Associate Administrator for International and Interagency Relations and Per Erik Opseth, Director, Geodetic Institute of the Norwegian Mapping Authority signing the agreement.NASA, Norway to Develop Arctic Laser-Ranging Station

    NASA and the Norwegian Mapping Authority are partnering to develop a state-of-the-art satellite laser ranging station 650 miles from the North Pole that will produce high-precision locations of orbiting satellites, help track changes in the ice sheets and improve the efficiency of marine transportation and agriculture.

    Under the new agreement signed on Aug. 7, Norway and NASA will build and install a satellite laser ranging facility in the scientific base of Ny-Ålesund, Svalbard. NASA will also provide expert consultation on how to operate the instruments. The ground-based laser transmits ultrashort laser pulses aimed at satellites specially equipped with a retroreflector, an array of special mirrors that bounce the pulses back. The system measures the time it takes for the light to travel back to its point of origin, which is used to determine the position of the satellite with respect to the ground station with an accuracy of around 0.04 inches (1 millimeter).

    View photos from the signing ceremony.


  • ESIP logoCDDIS has been accepted as an Earth Science Information Partners (ESIP) Type 1 member

    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.

  • ILRS logo2017 ILRS Technical Workshop: Second Circular

    The Institute of Astronomy at the University of Latvia and the International Laser Ranging Service (ILRS) will host the 2017 ILRS Technical Workshop on October 02 through 05, 2017 in Riga, Latvia. The second circular, containing important information about upcoming deadlines, is now available. The first circular for the workshop was issued in February 2017 and contains information about the workshop topics.

  • Cover of Journal of GeodesyPrinted version of the Journal of Geodesy Special Issue on VLBI now available

    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 This volume includes a Preface and 14 scientific articles devoted to various aspects of the VLBI theory, methodology and data analysis.

  • Canadian flagDr. Bill Petrachenko receives Career Service award

    Dr. Bill Petrachenko from NRCan has received a Career Service award from Canada’s Department of Natural Resources. More information is available on the NRCan website.

  • VLBI antennaJune 08, 2017 was a significant anniversary for VLBI

    In 1967, three groups -- one Canadian, another a collaboration between the National Radio Astronomy Observatory (NRAO) and Cornell University, and a third at MIT and Haystack Observatory -- were each working to achieve the first VLBI observation.

    Fifty years ago today, on June 8, 1967, one of the first such experiments was successfully carried out between Haystack and NRAO (see attached figure). In 1971, the American Academy of Arts and Sciences awarded its Rumford Prize to members of all three groups. The MIT and Haystack recipients were J.A. Ball, A.H. Barrett, B.F. Burke, J.C. Carter, P.P. Crowther, G.M. Hyde, J.M. Moran, A.E.E. Rogers.

  • Satellite laser ranging at GSFC Innovation column in GPS World discusses importance of laser ranging to GNSS satellites

    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.

  • 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

    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:

  • NASA logo Upcoming maintenance on CDDIS and ILRS email exploders

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

  • SGP logo Draft RFP for the SGSLR Network Build released

    The Draft RFP for the SGSLR Network Build has been released and can be found at

  • IDS logo Special collection of DORIS-related papers titled, "The Scientific Applications of DORIS in Space Geodesy", published in the journal "Advances in Space Research"

    The International DORIS Service (IDS) has just published in the journal "Advances in Space Research" a special collection of papers titled, "The Scientific Applications of DORIS in Space Geodesy". DORIS is one of the four fundamental techniques that contributes to the terrestrial reference frame. It is also a prime tracking technique for LEO satellites, including those that map the oceans with radar altimetry.

    The eighteen papers in the special issue cover five themes:

    • ITRF2014 -- the papers discuss the DORIS contribution to the new realization of the International Terrestrial Reference Frame (ITRF);
    • DORIS Ultra-Stable Oscillator (USO), Jason-2;
    • Precise Orbit Determination;
    • DORIS System and Network;
    • Intertechnique comparisons of DORIS products.

    The papers are published in Volume 58, Number 12 of the Journal Adv. Space Res. Of the 18 papers, four were led or featured significant contributions from NASA GSFC & JPL authors. The Guest Editors of the special issue were Frank G. Lemoine (Code 61A, Geodesy & Geophysics Laboratory, NASA GSFC) and Ernst J.O. Schrama (Faculty of Aerospace Engineering, Delft University of Technology, Delft, The Netherlands).

    This special issue marks the third time the DORIS community has published a special issue in a peer-reviewed journal dedicated to scientific and technical aspects of the DORIS technique. The previous special issues dedicated to DORIS were published in the journal Adv. Space Res. (two volumes in 2010) and in the Journal of Geodesy (2006).

    The papers of the current special issue (Vol. 58(12), Adv. Space Res, 2016) are available from the following URL:

    A full list of the papers with DOI and page numbers is provided below:

    Advances in Space Research
    Volume 58, Issue 12, Pages 2477-2774 (15 December 2016)

    Scientific Applications of DORIS in Space Geodesy
    Edited by Frank G. Lemoine and Ernst J.O. Schrama

    Lemoine, F.G., and E.J.O. Schrama, "Preface: Scientific Applications of DORIS in Space Geodesy", Adv. Space Res., 58(12), 2477-2478, 2016, doi: 10.1016/j.asr.2016.11.002.

    Moreaux, G., Lemoine, F.G., Capdeville, H., Kuzin, S., Otten, M., Štěpánek, P., Willis, P., Ferrage, P., "The International DORIS Service contribution to the 2014 realization of the International Terrestrial Reference Frame", Adv. Space Res., 58(12), 2479-2505, doi: 10.1016/j.asr.2015.12.021.

    Bloßfeld, M., Seitz, M., Angermann, D., Moreaux, G., "Quality assessment of IDS contribution to ITRF2014 performed by DGFI-TUM", Adv. Space Res., 58(12) 2505-2519, doi:10.1016/j.asr.2015.12.016.

    Lemoine, F.G.; Chinn, D.S.; Zelensky, N.P.; Beall, J.W.; Le Bail, K., in press., "The Development of the GSFC DORIS Contribution to ITRF2014", Adv. Space Res., 58(12), 2520-2542, doi: 10.1016/j.asr.2015.12.043.

    Soudarin, L., Capdeville, H., Lemoine, J.-M., "Activity of the CNES/CLS Analysis Center for the IDS contribution to ITRF2014", Adv. Space Res., 58(12), 2543-2560, doi: 10.1016/j.asr.2016.08.006.

    Kuzin, S., Tatevian, S., "DORIS data processing in the INASAN Analysis Center and the contribution to ITRF2014", Adv. Space Res., 58(12), 2561-2571, doi: 10.1016/j.asr.2016.07.010.

    Khelifa, S., "Noise in DORIS station position time series provided by IGN-JPL, INASAN and CNES-CLS Analysis Centres for the ITRF2014 realization", Adv. Space Res., 58(12), 2572-2588, doi: 10.1016/j.asr.2016.06.004.

    DORIS Ultra Stable Oscillator (USO)- Jason-2
    Belli, A., Exertier, P., Samain, E., Courde, C., Vernotte, F., Jayle, C., Auriol, A., "Temperature, radiation and aging analysis of the DORIS Ultra Stable Oscillator by means of the Time Transfer by Laser Link experiment on Jason-2", Adv. Space Res., 58(12), 2589-2600, doi: 10.1016/ j.asr.2015.11.025.

    Jayles, C., Exertier, P., Martin, N., Chauveau J.P., Samain E., Tourain C., Auriol A., Guillemot P., "Comparison of the frequency estimation of the DORIS/Jason2 oscillator thanks to the onboard DIODE and Time Transfer by Laser Link experiment", Adv. Space Res., 58(12), 2601-2616, doi: 10.1016/j.asr.2015.08.033.

    Willis, P., Heflin, M. B., Haines, B. J., Bar-Sever, Y. E., Bertiger, W. I., Mandea, M., "Is the Jason-2 DORIS Oscillator also Affected by the South Atlantic Anomaly?", Adv. Space Res., 58(12), 2617-2627, doi: 10.1016/j.asr.2016.09.015.

    Precise Orbit Determination
    Capdeville, H., Štěpánek, P., Hecker, L., Lemoine, J.M., "Update of the corrective model for Jason-1 DORIS data in relation to the South Atlantic Anomaly and a corrective model for SPOT-5", Adv. Space Res., 58(12), 2628-2650, doi: 10.1016/j.asr.2016.02.009.

    Zelensky, N.P., Lemoine, F.G., Chinn, D.S., Beckley, B.D., Bordyugov, O., Yang, X., Wimert, J.; Pavlis, D., "Towards the 1-cm SARAL orbit", Adv. Space Res., 58(12), 2651-2676, doi: 10.1016/j.asr.2015.12.011.

    Lemoine, J.M., Capdeville, H. Soudarin, L., "Precise orbit determination and station position estimation using DORIS RINEX data", Adv. Space Res., 58(12), 2677-2690, doi: 10.1016/j.asr.2016.06.024.

    DORIS System and Network
    Jayles, C.; Chauveau, J.P.; Didelot, F.; Auriol, A.; Tourain, C., "DORIS system and integrity survey", Adv. Space Res., 58(12), 2691-2706, doi:

    . Tourain, C., Moreaux, G., Auriol, A., Saunier, J., "DORIS Starec ground antenna characterization and impact on positioning", Adv. Space Res., 58(12), 2707-2716, doi: 10.1016/j.asr.2016.05.013.

    Saunier, J., Auriol, A., Tourain, C., "Initiating and error budget of the DORIS ground antenna position Genesis of the Starec antenna type C", Adv. Space Res., 58(12), 2717-2724, doi: 10.1016/j.asr.2016.02.013.

    Saunier, J., "Assessment of the DORIS network monumentation", Adv. Space Res., 58(12), 2725-2741, doi: 10.1016/j.asr.2016.02.026.

    Intertechinque Comparisons of DORIS Products
    Tornatore, V., Tanır Kayıkçı, E., Roggero, M., "Comparison of ITRF2014 station coordinate input time series of DORIS, VLBI and GNSS", Adv. Space Res., 58(12), 2742-2757, doi: 10.1016/j.asr.2016.07.016.

    Heinkelmann, R., Willis, P., Deng, Z., Dick, G., Nilsson, T., Soja, B., Zus, F., Wickert, J., Schuh, H., "Multi-technique comparison of atmospheric parameters at the DORIS co-location sites during CONT14", Adv. Space Res.,58(12), 2758-2773, doi: 10.1016/j.asr.2016.09.023.

  • CDDIS logo CDDIS successfully moves all primary operations to an upgraded computer system

    The CDDIS successfully moved all primary operations to an upgraded computer system on December 01, 2016; in total, the CDDIS archive was inaccessible to the user community for approximately 30 hours during the transition. The new IT infrastructure provides a more robust, reliable, and expandable system with increased storage capacity to handle future growth. All suppliers of data, derived products, and ancillary files for the CDDIS archive were required to modify their software to use the HTTP protocol for file upload. In addition to new hardware, the CDDIS archive processing software was redesigned and improved to provide for more efficient operations and additional QC on incoming files.

  • CDDIS logo CDDIS unavailable November 30-December 01 for transition to new systems

    On November 30, 2016 at 13:00 UTC, CDDIS will terminate all services (ftp, CDDIS/ILRS/SGP websites, data deliveries) as we transition to all new hardware and facilities. We are projecting about 24 hours to fully move to our new facilities and ensure all operations are back to normal. As such, all users need to plan on a 24+ hour disruption of service to the CDDIS archive with resumption of normal operations no earlier than December 01, 2016 at 17:00 UTC.

    In summary the following will take place:

    • 30 November 2016 at 13:00 UTC – All current production services (ftp, http, etc) will be shutdown.
    • 01 December 2016 at 17:00 UTC – all web and anonymous ftp access is restored for access to the archive. NOTE: restoration could occur sooner but no guarantees are made.
    • Currently used addresses, e.g., or, will continue to work as before the transition. However, if you are using a numeric IP address to access any CDDIS resources your scripts will fail as all current IP addresses will change during the transition.
    • 02 December 2016 – All CDDIS operations should be returned to normal service.

    While CDDIS is unavailable, users can access one of the other data centers supporting the services:

    All questions on the CDDIS transition should be directed to

  • SGP logo Space Geodesy Project Issues Solicitation for New VLBI Antennas

    The Space Geodesy Project posted a request for proposal for the construction, deployment and commissioning of up to three Very Long Baseline Interferometer (VLBI) antennas that will be part of the new NASA Space Geodesy Network (NSGN) and the VLBI2010 Global Observing System (VGOS). Details on the solicitation can be found here:

  • NASA logo Brief network outages at GSFC on September 03, 2016
    08/30/2016 Work will be performed on the NASA GSFC network infrastructure from 09:00 a.m. EDT (13:00 UTC) through 05:00 p.m. EDT (21:00 UTC) on Saturday, September 03, 2016. Users may experience short intermittent interruptions in connectivity to CDDIS web and ftp sites during that time period.

    Should the CDDIS be unaccessible, users can access one of the other data centers supporting the services:

    We regret any problems this work may cause the user community.

  • Dr. Erricos Pavlis User Profile: Dr. Erricos C. Pavlis

    NASA Earthdata has published a user profile of Dr. Erricos Pavlis as part of their "Who uses NASA Earth science data?" series

  • 20th ILRS Workshop banner First Circular for the 20th International Workshop on Laser Ranging Released

    GFZ Potsdam and the International Laser Ranging Service (ILRS) are pleased to announce that the 20th International Workshop on Laser Ranging will be held in Potsdam Germany during the week of October 09-14, 2016 at GFZ Potsdam, Telegrafenberg. The first circular has been released.

  • March 2016 cover of the European Physical Journal LARES + LAGEOS 1&2 Lense-Thirring results selected as EPJ-C cover

    The article, "A test of general relativity using the LARES and LAGEOS satellites and a GRACE Earth gravity model," (Ciufolini et. al.) has been published in the March 2016 issue of the European Physical Journal-C. Furthermore, a figure from this paper has been selected for the cover of that issue.

  • Crustal Dynamics Project logo. The passing of Dr. Bob Coates

    We are saddened to report the passing of Dr. Bob Coates, a long time colleague in the field of space geodesy. Bob was the Project Manager for NASA’s very successful Crustal Dynamics Project (CDP). Bob helped advance the SLR and VLBI technologies at NASA GSFC, incorporating them as the key measurement components of the CDP, which succeeded in describing the relative motions of the Earth’s plates with unprecedented accuracies. He will be remembered for his many contributions in both science and engineering, and for his guidance and encouragement to those who worked in the program.

  • image of upper part of a clock showing numbers 11, 12 and 1. Positive leap second to be introduced

    A positive leap second will be introduced at the end of December 2016. More information is available from the IERS.

  • Earthdata logo NASA Space Geodesy Data for Precise Orbit Determination of Altimeter Satellites Webinar (NASA Earthdata webinar series)

    Over the last 25 years, ocean radar altimeter satellites have revolutionized our understanding of the world’s oceans. Today six altimeter satellites from different national and international space agencies synoptically measure the ocean surface topography in order to determine how the ocean surface changes with time. The heart of the altimeter measurement is the precise determination of the orbit reference which is used as the basis from which the changes in the ocean surface are determined. We now routinely determine the orbits of the joint NASA/CNES/NOAA/EUMETSAT missions Jason-2 and Jason-3 with a radial RMS precision of 1 cm.

    This webinar describes how we can compute these orbits with such accuracy, and will further outline how these computations rely directly and indirectly on a suite of international Space Geodesy data as well as data from different NASA satellites.

  • LAGEOS satellite Norway's contribution to the Global Geodetic Reference Frame

    From the Norwegian Mapping Authority: Norway's contribution to the Global Geodetic Reference Frame: The Geodetic Earth Observatory in Ny-Ålesund, Svalbard. The UN General Assembly has adopted its first resolution recognising the importance of geodesy. Norway co-chaired work on the first UN resolution. Its most important contribution is the Norwegian Mapping Authority's geodetic Earth observatory in Ny-Ålesund on Svalbard. This is the northernmost facility of its kind, and plays a key role in a global network for observation and research. Data acquired here are important for climate research and monitoring.

  • LAGEOS satellite Now 40, NASA's LAGEOS Set the Bar for Studies of Earth

    On May 4, 1976, NASA launched a cannonball-shaped satellite that transformed studies of Earth’s shape, rotation and gravity field.

    LAGEOS – short for Laser Geodynamic Satellite – was the first NASA orbiter dedicated to the precision measurement technique called laser ranging. With it, scientists have measured the movement of Earth’s tectonic plates, detected irregularities in the rotation of the planet, weighed it, and tracked small shifts in its center of mass.

    Small deviations in the satellite’s orbit were used to develop early models of Earth’s gravitational field. Further perturbations in the orbit helped explain how sunlight heating small objects can affect their orbits, including near-Earth asteroids.


  • Carey Noll Data Chat: Carey Noll
    04/28/2016 NASA Earthdata has published an interview with CDDIS Manager Carey Noll as part of their "Data chat" series.

    Read more....
  • 12-meter (39-foot) antenna at the Kōke‘e Park Geophysical Observatory in Hawaii NASA Station Leads Way for Improved Measurements of Earth Orientation, Shape
    03/10/2016 NASA has demonstrated the success of advanced technology for making precise measurements of Earth’s orientation and rotation – information that helps provide a foundation for navigation of all space missions and for geophysical studies of our planet.

    The technology includes a new class of radio antenna and electronics that provide broadband capabilities for Very Long Baseline Interferometry, or VLBI. This technique is used to make precise measurements of Earth in space and time.

    VLBI measurements have been conducted for decades using a worldwide network of stations that carry out coordinated observations of very distant astronomical objects called quasars. To meet the demand for more precise measurements, a new global network of stations, called the VLBI Global Observing System, or VGOS, is being rolled out to replace the legacy network.

    Read full article.
  • map of the world NASA Contributes to Global Standard for Navigation, Studies of Earth
    02/25/2016 The surface of Earth is constantly being reshaped by earthquakes, volcanic eruptions, landslides, floods, changes in sea levels and ice sheets, and other processes. Since some of these changes amount to only millimeters per year, scientists must make very precise measurements of the landscape and ocean in space and time in order to study their evolution and help mitigate their impacts.

    Read full article.
  • NASA logo Satellite Laser Ranging Research Geophysicist Position at NASA/GSFC
    01/13/2016 The Sciences & Exploration Directorate, Solar System Exploration Division, Laser Remote Sensing Laboratory (Code 694) at NASA Goddard Space Flight Center is seeking a research scientist to provide expertise in space geodesy and Satellite Laser Ranging (SLR) system development and operations. As a Research Geophysicist, the successful candidate will be responsible for conducting, managing, planning, and directing the research and development of NASA’s next generation SLR stations. Conceives and conducts instrument and systems development to increase fundamental knowledge and understanding of space geodesy via SLR. Serve as a technical leader for the implementation of new NASA SLR stations as part of the NASA Space Geodesy Network (NSGN), and ensure the operational NSGN produces the data required by NASA missions and the scientific community. Identify problems and requirements for making geodetic SLR observations to best achieve an improved understanding of Earth dynamic processes, and initiating new experiments and programs to address these problems. Responsible for the development of new and novel applications of the SLR technique. Participate in the writing and publication of significant scientific and technological findings in appropriate journals and other media. Give presentations at scientific and technical meetings, both nationally and internationally. Responsible for defining, articulating, advancing, and publicizing NASA's role in the worldwide SLR community and participating in the direction of international organizations using SLR results and supporting SLR activities. This includes leading and supporting activities of the International Satellite Laser Ranging Service (ILRS). Work closely with NASA and NASA partner mission owners to develop SLR related requirements on the mission, associated retroreflectors, and the operational SLR network to meet the mission's science requirements. Applicants should have experience in instrument design, research and development of precision laser ranging and related optical measurement systems (such as SLR, LIDAR, and laser interferometers) and their application to space geodesy, geoscience, and/or Earth observations. Further information about NASA’s Space Geodesy Project can be found at:

    U.S. citizenship is required. To view the full vacancy announcement, which contains further information including qualification requirements and application instructions, go to ( Applications must be received by February 29, 2016 via the USAJobs website. For additional questions, please contact Dr. Stephen M. Merkowitz at

    NASA GSFC is an Equal Opportunity Employer.

  • NASA logo Brief network outages at GSFC on December 19, 2015
    12/11/2015 Work will be performed on the NASA GSFC network infrastructure from 03:00 p.m. (20:00 UTC), Saturday, December 19, 2015 through 03:00 a.m. (08:00 UTC) on Sunday, December 20. Users can expect 10-15 minute interruptions during that time period.

    Should the CDDIS be unaccessible, users can access one of the other data centers supporting the services:

    We regret any problems this work may cause the user community

  • Site Requirements image New "Site Requirements for GGOS Core Sites" document released
    12/02/2015 Version 2 of the document Site Requirements for GGOS Core Sites has been issued.

  • Space Geodesy VLBI Antenna Request for Information Released
    10/06/2015 The National Aeronautics and Space Administration (NASA) Space Geodesy Project (SGP) is soliciting information to improve its understanding of the interest, capabilities, and Rough Order of Magnitude (ROM) estimates for planning the construction and deployment of up to three Very Long Baseline Interferometer (VLBI) antennas that will be part of a new NASA Space Geodesy Network (NSGN) and the VLBI2010 Global Observing System (VGOS).

    Read more..
  • Antenna pedestal installed on the concrete padKPGO blogRelease Date: 09/04/2015 The Space Geodesy Project is pleased to announce a new blog. This blog follows the implementation of the Space Geodesy Project’s new 12-meter broadband Very Long Baseline Interferometry (VLBI) station at NASA’s Kōkeʻe Park Geophysical Observatory (KPGO) on Kauai, Hawaii. The new station is a joint effort by NASA Goddard Space Flight Center and the United States Naval Observatory, and will become part of the VLBI2010 Global Observing System (VGOS). The station design is based on the successful prototype VLBI2010 station at NASA’s Goddard's Geophysical and Astronomical Observatory (GGAO) in Greenbelt, MD. The new KPGO antenna was developed by Intertronics Solutions, Inc. (ISI), and the MIT Haystack Observatory is responsible for the development of the broadband signal chain.
  • Photo of Michael PearlmanMichael Pearlman awarded the 2014 Golden Medal of MeritRelease Date: 08/28/2015 In April 2015, Michael Pearlman, Director of the ILRS Central Bureau, was awarded the 2014 Golden Medal of Merit by the Scientific Board of the Institute of Applied Astronomy of the Russian Academy of Sciences in recognition of his achievements and contributions in laser ranging and international scientific programs. The citation for the award read: "For outstanding contribution to the development of space geodesy and for promoting the IAA RAS role in creation and enhancement of GGOS." Mike visited the Institute of Applied Astronomy in Saint Petersburg in April and accepted the award during a ceremony in conjunction with the 6th All-Russian Meeting "Fundamental and Applied Positioning, Navigation and Timing" (PNT-2015). Mike also participated in the conference and gave a talk titled, "The Global Geodetic Observing System (GGOS) and the Important Role played by the Institute of Applied Astronomy, ROSCOSMOS, and other Russian Participants."
  • Earth with satellites orbiting around it.Third GNSS Tracking CampaignRelease Date: 08/05/2015 The third SLR GNSS Tracking Campaign will run from August 10 through October 16 (10 weeks). The focus will be on the following GNSS satellites:

    • GLONASS-123, -125, -128, -129, -133, and -134
    • Compass-M3
    • Galileo-101, -102, -103, and -104

    The revised priority list reflecting these changes for the third campaign is now available on the ILRS website at: The results from this campaign will be a topic of discussion at the upcoming ILRS Technical Workshop to be held October 26 - 30 in Matera (

    Goals and instructions
  • Earth with satellites orbiting around it.Results from Second GNSS Tracking CampaignRelease Date: 07/31/2015 The second GNSS Tracking Campaign was held November 28, 2014 through February 28, 2015. To keep the document at a manageable size, it focuses on the 14 most productive sites in this campaign. The report can be accessed on the activities link in the LARGE Study Group section of the ILRS website.
  • CDDIS logoCDDIS Earthdata webinar, "Distributing Real-Time GNSS Data and Derived Products at the CDDIS"Release Date: 07/22/2015 The CDDIS held an Earthdata webinar titled, "Distributing Real-Time GNSS Data and Derived Products at the CDDIS". This webinar provides an overview of the Global Navigation Satellite System (GNSS), the International GNSS Service (IGS), Real-time GNSS, the CDDIS real-time data caster and protocol, the registration process before accessing the real-time data, and several demonstrations on configuring and using the client software.

  • ILRS logoILRS Technical Workshop (26-30 October 2015, Matera, Italy) Abstract SubmissionRelease Date: 07/20/2015 Author: Cinzia Luceri/Giuseppe Bianco

    At the next ILRS Technical Workshop (26-30 October 2015, Matera, Italy) session chairs will designate key people to present position papers to introduce topics and set the scene for discussion. Abstracts for these position papers must be submitted through the abstract submission process. Other abstracts may be submitted for oral and poster presentations. Oral presentations must be relevant to a particular session and address some of the key questions identified in the session description. Oral presentations will go through an approval process by session chairs so they can plan an orderly program including sufficient time for discussion. Presentations should be short and informative. All presentations not accepted for oral talks may be given as posters. We view posters as a very important part of the meeting; they provide one-on-one opportunity for discussion on key features of the papers. Participants are welcome to submit abstracts for any or all sessions.

    We need broad participation in the session discussions. In addition to the scheduled talks, participants are encouraged to bring one or two charts to stress or support particular points and issues in the discussion. Look carefully at the questions listed for each session. These charts will be uploaded before each session but do not require a submitted abstract. The Session Chairs will coordinate this activity. All charts will be included in the workshop proceedings.

    The opportunity to submit abstracts is now open, deadline September 30th, 2015.
    Please, use the conference website
  • Quasarville: The town that never movesNASA Explains Why June 30 Will Get Extra SecondRelease Date: 06/26/2015 The day will officially be a bit longer than usual on Tuesday, June 30, 2015, because an extra second, or "leap" second, will be added.

    "Earth's rotation is gradually slowing down a bit, so leap seconds are a way to account for that," said Daniel MacMillan of NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

    Strictly speaking, a day lasts 86,400 seconds. That is the case, according to the time standard that people use in their daily lives – Coordinated Universal Time, or UTC. UTC is "atomic time" – the duration of one second is based on extremely predictable electromagnetic transitions in atoms of cesium. These transitions are so reliable that the cesium clock is accurate to one second in 1,400,000 years.

    However, the mean solar day – the average length of a day, based on how long it takes Earth to rotate – is about 86,400.002 seconds long. That's because Earth's rotation is gradually slowing down a bit, due to a kind of braking force caused by the gravitational tug of war between Earth, the moon and the sun. Scientists estimate that the mean solar day hasn't been 86,400 seconds long since the year 1820 or so.

    This difference of 2 milliseconds, or two thousandths of a second – far less than the blink of an eye – hardly seems noticeable at first. But if this small discrepancy were repeated every day for an entire year, it would add up to almost a second. In reality, that's not quite what happens. Although Earth's rotation is slowing down on average, the length of each individual day varies in an unpredictable way.

  • photo of Bob SchutzThe passing of Dr. Bob SchutzRelease Date: 06/11/2015We are sad to announce that our colleague and friend, Dr. Bob Schutz, University of Texas at Austin/Center for Space Research (CSR) passed away on June 7, 2015, surrounded by family.

    Bob was a member of the faculty at the University of Texas since 1969. His research interests included space geodesy and its applications, space geodetic instrumentation, precise orbit determination, orbital mechanics, mission planning and computational techniques. He was the science team leader for NASA's Geoscience Laser Altimeter System (GLAS), an instrument used to measure topography, especially the changes in Antarctic and Greenland ice sheets, that operated on the Ice, Cloud, and land Elevation Satellite (ICESat) in Earth's orbit for seven years.

    Bob was recently elected a member of the National Academy of Engineering (NAE), and he was a fellow of the American Institute of Aeronautics and Astronautics, the American Geophysical Union, and the American Astronautical Society. Most recently, he held the Joe J. King Chair in Engineering and the FSX Professorship in Space Applications and Exploration at the University of Texas at Austin. Bob was also a special friend of the IAG Services, participating in many activities over the years and giving advice both in the early days and through recent years. His IAG contributions including being a co-founder of the International Laser Ranging Service (ILRS), and being closely involved in the IGS (International GPS Service, now the International GNSS Service) since its inception in the early 1990s, serving most recently on the ILRS Governing Board.

    Bob was a cherished colleague, a Ph.d advisor, mentor and a fine gentleman. His legacy will be appreciated for many years to come. We wish to pass on our condolences to Bob’s family, friends, and colleagues around the world. We will truly miss him.
  • NASA logoNASA network connectivity outageRelease Date: 04/22/2015 Starting this Sunday, April 26, there will be a scheduled outage for NASA network connectivity, from April 26 17:00 UTC through April 27 05:00 UTC. We have been told that the NASA network will be unavailable during the first four hours; intermittent outages of several minutes can be expected after that time until the end of the period specified above. During the outage, the ILRS, CDDIS, and Space Geodesy Project websites will not be accessible.

    While the CDDIS is unavailable, users can access one of the other data centers supporting the services:

    IGS RTS:
    ILRS: (consult prior to outage)

    We regret any problems this outage may cause the user community.
  • World map depicting locations of GNSS sites Real-Time GNSS Data and Products now available through the CDDISRelease Date: 04/10/2015 The CDDIS staff is pleased to announce that its real-time caster is now operational, supporting the International GNSS Service (IGS) Real-Time Service (RTS). The IGS RTS, based on a cooperative global infrastructure of stations, data centers, and analysis centers, provides GNSS orbit and clock corrections that enable precise point positioning (PPP) and related applications, such as time synchronization and disaster monitoring at global scales. The CDDIS caster utilizes the NTRIP (Networked Transport of RTCM via Internet Protocol) software to disseminate these real-time streams to registered users.

    The CDDIS has incorporated the EOSDIS User Registration System (URS) to handle user signup and access authentication. At this time, the CDDIS is making real-time data available from 155 sites (see map) as well as 37 product streams. Future plans include the addition of more station data streams and computation and conversion of these data streams into high‐rate data files for the CDDIS online archive. More information about the CDDIS caster and real-time data and products is available from the CDDIS website:
  • A speed bump in space-time Earthdata Article Featuring CDDIS PublishedRelease Date: 12/04/2014 Like many physicists today, Rafael Lang at Purdue University is on the hunt. As in a treasure hunt, the odds of finding the treasure may be slim, but the rewards are huge and the lure of the hunt irresistible. Lang said, "If we were to find something, it would be super, super exciting, another puzzle piece to open this new world."

    Read more
  • 19th ILRS workshop logo 19th International Workshop on Laser Ranging a great successRelease Date: 11/18/2014 The 19th International Laser Ranging Workshop was hosted by NASA GSFC from October 27-31, 2014 in Annapolis, Maryland. October 31 marks the 50th anniversary of the first successful Satellite Laser Ranging (SLR) measurement which occurred at the Goddard Geophysical and Astronomical Observatory (GGAO) in 1964. The theme for this workshop, "Celebrating 50 Years of SLR: Remembering the Past and Planning for the Future" allowed the community to look back on its many accomplishments and to present plans for future advances in SLR technology and science. Sponsors for the Workshop were NASA, the Smithsonian Astrophysical Observatory (SAO), and the International Laser Ranging Service (ILRS). The Workshop was organized by Carey Noll (NASA GSFC, CDDIS DAAC Manager), Jan McGarry (NASA GSFC), Mike Pearlman (SAO) and Stephen Merkowitz (NASA GSFC) and was attended by approximately 180 participants from 25 countries.

    On Monday, the history of SLR was given in a series of six invited talks by the pioneers in the field. The afternoon was devoted to invited science talks showing SLR's positive impact on various NASA and international missions.

    In addition to the events in Annapolis, the participants were given a day-long tour of GSFC and GGAO, including tours of the Goddard Visitor's Center, Building 7 Integration and Testing facilities, Building 29 James Webb Space Telescope (JWST) integration and testing, and tours of the NASA next generation space geodesy systems at GGAO. A Goddard Joint Engineering and Scientific Colloquium on Wednesday featured a seminar by John Degnan, "A Celebration of Fifty Years of Satellite Laser Ranging." John's talk was introduced with a few words from GSFC Center Director, Chris Scolese.

    A new format for a station operations session was introduced at this workshop where ILRS experts met in small groups of station engineers and operators to provide solutions to common station problems, information to maintain station stability, and guidelines for interacting with the analysts in determining station biases. These station clinics were well attended and received by workshop attendees.

    A highlight of the Workshop was a speech and question and answer session at Thursday evening's banquet given by Dr. Piers Sellers, GSFC Deputy Director of the Sciences and Exploration Directorate and NASA astronaut.

    There were 81 oral presentations and 70+ posters at the Workshop. The Goddard participants were authors or co-authors of over 30 of these, with many highlighting the new Space Geodesy Satellite Laser Ranging (SGSLR) Systems and the Next Generation Space Geodesy Network. SGSLR and the Space Geodesy Network will be built by Space Geodesy Project at Goddard for global deployment over the coming decade.

    This workshop in Annapolis and GSFC proved to be a very successful gathering of international experts in the field of satellite laser ranging. The workshop website ( will soon be updated with presentations, posters, summaries, and photos from the week.
  • 19th ILRS workshop logo 19th International Workshop on Laser Ranging - Celebrating 50 years of SLRRelease Date: 09/24/2014 The National Aeronautics and Space Administration (NASA), along with the Smithsonian Astrophysical Observatory, and the International Laser Ranging Service (ILRS), are pleased to announce that the 19th International Workshop on Laser Ranging will be held in Annapolis Maryland during the week of October 27-31, 2014 at the Historic Inns of Annapolis.

    October 31, 2014 will mark the 50th anniversary of the first successful SLR measurement, conducted at what is now the Goddard Geophysical and Astronomical Observatory (GGAO). The theme for this workshop, "Celebrating 50 Years of SLR: Remembering the Past and Planning for the Future" will allow us to look back on our many accomplishments and present plans for future advances in SLR technology and science.

    Visit the workshopp web site
  • NGSLR Celebrating 50 Years of Satellite Laser Ranging at NASA Goddard Space Flight CenterRelease Date: 08/28/2014 We like to think of Earth as a big blue marble; a shimmering, smooth sphere. In reality, our home planet is shaped more like a big blue potato (or, to be polite and more scientific, an "oblate spheroid"). The combination of Earth’s rotation at roughly 1,670 kilometers per hour, the uneven distribution of continents that are slowly moving, the Moon’s tug on tides, ocean circulation, and a host of other factors cause our planet to have an uneven surface that is a bit flat at the poles and slightly bulging around the middle.

    This means that the Earth’s exact shape, center of gravity, and precise rotation are constantly changing and can only be determined through extremely precise measurements. An entire field of science called geodesy is devoted to taking these precise measurements, and Goddard Space Flight Center is at the leading edge of this field. In fact, it was in a field near Goddard 50 years ago this October that the first successful Satellite Laser Range (SLR) measurements were taken, ushering in a new era in the science of measuring the Earth.

    Read more
  • GGIM Logo Ruth Neilan (NASA JPL) appointed to the rank of official U.S. Delegate Advisor for the United Nations to UN Global Geospatial Information Management (GGIM)Slide showRelease Date: 08/26/2014 During the week of August 4-8, Ruth Neilan (NASA JPL) participated in and attended the following meetings at the United Nations in New York, Department of Economic and Social Affairs, UN Statistics Division:
    • Fourth Session of the United Nations Committee of Experts on Global Geospatial Information Management (UN-GGIM)
    • United Nations Global Forum on the Integration of Statistical and Geospatial Information
    • Global Geodetic Reference Frame (GGRF) Working Group Meeting
    • UN-GGIM regional splinter sessions

    Because of her involvement in these critical areas, Ruth has been appointed to the rank of official U.S. Delegate Advisor for the United Nations to UN GGIM.

    On August 4-5, a meeting was held on "The Integration of Statistical and Geospatial Information" with significant focus on the Global Geodetic Reference Frame (GGRF). Wednesday, August 6, began with a workshop on the GGRF. The GGRF Working Group is chaired by Australia and Norway (Gary Johnston, Anne Jørgensen and Per Erik Opseth); included in the core working group (WG) are Zuheir Altamimi, Hansjörg Kutterrer, and Ruth Neilan, as key members of the GGRF working group; with larger WG including many country representatives.

    The GGRF Working Group tabled a Terms of Reference, a draft UN General Assembly Resolution for the GGRF, and a Concept Note at the 4th Session of the UN Community of Experts on GGIM. After a presentation given by Gary Johnston on August 6, there were 40 extremely positive interventions in support of the work of GGRF – the sheer number of countries formally declaring support for this effort is remarkable and demonstrates that the GGIM's work has had significant impact in the diplomatic sphere.

    The draft resolution and its intent were approved by the 77 representative countries. This resulted in an official decision, 4/101, recommending that the amended draft Resolution on a Global Geodetic Reference Frame for Sustainable Development, be referred to the Economic and Social Council for endorsement and further referral to the United Nations General Assembly. The decision also noted the commitment of Member States to provide support in this process.

    This resolution, and the tremendous diplomatic and technical effort behind it, highlights the importance of the global geodetic reference frame, its maintenance, upgrade, and collocation of techniques. Additional time was spent in the WG on August 8, laying out the 'GGRF Roadmap' and other supporting strategies. Related documents and information about the GGRF meeting can be found on the web at:

    GEO Secretariat, Barb Ryan, was also present at the GGRF workshop and voiced her support of the GGRF on behalf of GEO. In complement to this, Ryan has written a strong support letter for GGRF and will work jointly with the team within the GEO/CEOS committees and the UN GGIM. This will also be a topic at the UN International Committee on GNSS within UN OOSA, which hosted a UN GGIM preparatory meeting this past April in Vienna, Austria.

    For the official UN press release detailing the sessions of the UN Committee of Experts on GGIM and links to corresponding documents, please visit:

    More information on the GGIM Global Forum, August 4-5 can be found at:

    Space Geodesy Community Representatives:
    • Gary Johnston, Geoscience Australia; Chair of GIAC, Member of the IGS Governing Board
    • Per Erik Opseth and Anne Jørgensen, Norwegian Mapping Authority (Kartverket), NASA partners, Ny Alesünd Station
    • Zuheir Altamimi, Institut National de l'Information Géographique et Forestière (IGN); ITRF and Member of the IGS Governing Board
    • Hansjörg Kutterrer, Bundesamt für Kartographie und Geodäsie (BKG); Chair of GGOS
    • Ruth Neilan, NASA JPL; Vice Chair of GGOS, Director of the IGS Central Bureau
  • 18th Laser Ranging Workshop logo Proceedings from the 18th International Workshop on Laser Ranging Release Date: 03/25/2014 A website for the proceedings from the 18th International Workshop on Laser Ranging, held November 11-15, 2013 in Fujiyoshida Japan, has been created and is now available at

    Because a hardcopy of the proceedings will not be published, all presentations, posters, and papers collected thus far have been made available through this website. Session summaries and ILRS splinter meeting notes are also linked on the website. The ILRS would like to acknowledge the significant, and thorough, efforts of the program committee in working with workshop participants to collect the documents that are now available through the website.
  • CDDIS Logo New CDDIS website now availableRelease Date: 03/24/2014 The CDDIS staff is pleased to announce a new CDDIS website is now available. This redesign has allowed for a review of the organization of the site and its contents, ensuring information is current and useful. The new site also incorporates an improved navigation scheme. The website features access to applications enabling data discovery. One application, the SiteLogViewer, provides an enhanced display and comparison of the contents of ILRS and IDS site logs used by the services to document a site's system configuration; IGS and IVS site logs will be added to the utility in the near future.

    Comments and suggestions are welcome and should be directed to the CDDIS support group through the "Contact Us" link. We would like to acknowledge the efforts of the website development team (Lori Tyahla, Nathan Pollack, and Carey Noll) for their contributions to the site content.
  • Goddard Logo Robert H. Goddard Award RecipientsRelease Date: 03/18/2014 Congratulations to the Space Geodesy Project Team for receiving the Robert H. Goddard Exceptional Achievement Group Award for Engineering (group photos GSFC | MIT). Additional congratulations goes to Jan McGarry, who received an individual Robert H. Goddard Award for Exceptional Engineering Achievement.
  • NASA logo Network outage - Saturday, March 15, 2014 from 08:00 a.m. through 04:00 p.m. EDT (12:00-20:00 UTC) Release Date: 03/07/2014 We have been notified that there will be a network outage (due to work on NASA's backbone equipment) on Saturday, March 15, 2014 from 08:00 a.m. through 04:00 p.m. EDT (12:00-20:00 UTC). Unfortunately, this activity will affect CDDIS operations. All connectivity to our servers will be off-line during that time. The outage will also affect access to the CDDIS, ILRS, LRO-LR, and Space Geodesy Project websites.

    While the CDDIS is unavailable, users can access one of the other data centers supporting the services:

    We regret the inconvenience the outage will cause our user community.
  • Space Geodesy Project logo NASA Solar System Exploration Division Seminar Release Date: 01/29/2014 An SSED seminar will be held Monday, February 10 from 2 to 3 p.m. in Building 34, Room W150. The speaker, Dr. Zuheir Altamimi from IGN in France, will give a presentation entitled "The International Terrestrial Reference Frame: current status and future challenges."
  • ILRS logo 19th International Workshop on Laser Ranging AnnouncedRelease Date: 01/21/2014 We are pleased to announce that the 19th International Workshop on Laser Ranging will be hosted at NASA Goddard Space Flight Center, October 27-31 2014. Goddard has the unique opportunity to host this event at the birthplace of SLR: October 31, 2014 will mark the 50th anniversary of the first SLR measurement, conducted at what is now the Goddard Geophysical and Astronomical Observatory, GGAO. The theme for this workshop, "Celebrating 50 Years of SLR: Remembering the Past and Planning for the Future" will allow us to look back on our many accomplishments and present plans for future advances in the SLR technique. Furthermore, we solicit contributions from complementary space geodesy techniques and from activities that rely on the integration of SLR with other space geodesy techniques.

    Please consider participation in this workshop and reserve the week to join us at NASA GSFC. More details will be provided shortly.
  • NASA logoNASA Earth and Space Science Fellowship (NESSF) Program Release Date: 12/23/2013 NASA announces a call for graduate fellowship proposals to the NASA Earth and Space Science Fellowship (NESSF) program for the 2014-2015 academic year. This call for fellowship proposals solicits applications from accredited U.S. universities on behalf of individuals pursuing Master of Science (M.Sc.) or Doctoral (Ph.D.) degrees in Earth and space sciences, or related disciplines. The purpose of NESSF is to ensure continued training of a highly qualified workforce in disciplines needed to achieve NASA’s scientific goals. Awards resulting from the competitive selection will be made in the form of training grants to the respective universities.

    The deadline for NEW applications is February 3, 2014, and the deadline for RENEWAL applications is March 17, 2014.

    The NESSF call for proposals and submission instructions are located at the NESSF 14 solicitation index page at - click on "Solicitations" then click on "Open Solicitations" then select the "NESSF 14" announcement. Also refer to "Proposal Submission Instructions" and "Frequently Asked Questions" listed under "Other Documents" on the NESSF 14 solicitation index page.

    All proposals must be submitted in electronic format only through the NASA NSPIRES system. The advisor has an active role in the submission of the fellowship proposal. To use the NSPIRES system, the advisor, the student, and the university must all register. Extended instructions on how to submit an electronic proposal package are posted on the NESSF 14 solicitation index page listed above. You can register in NSPIRES at

    For further information contact Claire Macaulay, Program Administrator for NESSF Earth Science Research, Telephone: (202) 358-0151, E-mail: or Dolores Holland, Program Administrator for NESSF Heliophysics Research, Planetary Science Research, and Astrophysics Research, Telephone: (202) 358-0734, E-mail:
  • Link to full articleNASA and US Air Force reach agreement Release Date: 09/06/2013 An agreement was reached between NASA and the US Air Force concerning the hosting of NASA supplied laser retroreflector arrays onto future GPS satellites. This agreement gives NASA the formal approval to move forward with the GPS Laser Retroreflector Array (GPS-LRA) Project that will supply the retroreflectors for the GPS-III satellites starting with SV-9.

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  • 18th International Workshop on Laser Ranging Logo18th International Workshop on Laser Ranging Release Date: 07/19/2013 Registration and abstract submission for the 18th International Workshop on Laser Ranging are now open. Participants are all requested to fill out these forms by 20 September. The overall schedule in the workshop week, including the opening lectures on Monday morning by Dr J J Degnan and Dr M Fujita, can be found on the workshop website.

    Read more
  • California's Chariot Fire affects Monument Peak operationsRelease Date: 07/15/2013 The Chariot Fire in southern California has required the shutdown of operations at NASA's MOBLAS-4 SLR station in Monument Peak. The crew safely evacuated on Monday July 8th and returned July 12th. The station has safely returned to operations. The fire reached within a mile of the station. (Photo courtesy of

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  • NASA Forms Space Geodesy Working Group
    05/30/2013 NASA has formed the Space Geodesy Working Group to perform fact-finding related to the scientific, technical, and organizational issues associated with the ongoing development of its Space Geodesy Program. The term of service for the Space Geodesy Working Group is three years. The Working Group is tasked to:

    • Conduct semi-annual reviews of the Space Geodesy Program to include reviews of the Program's scientific requirements, strategies, and technical approaches; and
    • Provide technical findings to NASA on its evaluations of and options for resolving program and project challenges following each semi-annual review.

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  • Space Geodesy SLR Request for Information Released
    05/02/2013 The National Aeronautics and Space Administration (NASA) Space Geodesy Project (SGP) is soliciting information to improve its understanding of the interest, capabilities, and Rough Order of Magnitude (ROM) estimates for planning the construction, deployment, and operation of the next generation Space Geodesy (SG) Satellite Laser Ranging (SLR) Stations that will be part of a new NASA’s Space Geodetic Network (SGN). NASA is considering the construction of up to ten new SLR stations that will contribute to the larger Global Geodetic Observing System (GGOS).

    Read more
  • 18th International Workshop on Laser Ranging Logo The first announcement of the next International Workshop on Laser Ranging has been issued.Release Date: 04/23/2013 The 18th International Workshop on Laser Ranging is organized so that worldwide scientists and engineers in this and related fields can exchange their views, share opinions on the on-going problems, and navigate the future.

    The theme of this year's workshop is "Pursuing Ultimate Accuracy & Creating New Synergies." In addition to the important topic of maximizing accuracy, this workshop is intended to enhance the potential of laser ranging with the inclusion of activities in relevant fields.

    The workshop will take place November 11-15, 2013 at the Highland Resort Hotel, Fujiyoshida, Japan. More information is available on the workshop website:

    Please consider your participation and reserve the week now. The procedures for the registration (including hotel booking) and the abstract submission will be announced in July. Please contact the local organizing committee ( for additional information.
  • ITRF2013 Call for Participation
    03/28/2013 Please be informed that the ITRF2013 Call for Participation is now released and could be retrieved at the ITRF web site, using the following link:

    In addition to the solicited global solutions from the four space geodesy techniques (to be provided by the Technique Services), we also solicit and encourage the owners of co-location sites to consider conducting new local tie surveys using the most up to date survey methods. Indeed, the local ties available at the ITRS Center for a certain number of co-location sites are now old by 10 to 20 years. In this respect, we would greatly appreciate the contribution of the national mapping and space agencies investing and operating co-location sites, which constitute the main foundation of the ITRF. More details regarding the local tie survey are available in the ITRF2013 CfP.
  • Earth Orientation Animations
    03/01/2013 When you think of the Earth’s orientation, you’d probably imagine something like a globe, where it always rotates around an axis, called the spin axis, defined by the north and south poles. And while this generally makes sense, in reality, the Earth’s orientation is constantly changing very slightly, and this change can be described in three ways. Learn more about how the Earth's orientation changes by watching these animations.

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  • NASA Beams Mona Lisa to Lunar Reconnaissance Orbiter at the Moon
    01/28/2013 Laser communication and ranging experiments were successfully conducted from the satellite laser ranging (SLR) station at NASA Goddard Space Flight Center (GSFC) to the Lunar Reconnaissance Orbiter (LRO) in lunar orbit. The experiments used 4096-ary pulse position modulation (PPM) for the laser pulses during one-way LRO Laser Ranging (LR) operations. Reed-Solomon forward error correction codes were used to correct the PPM symbol errors due to atmosphere turbulence and pointing jitter. The signal fading was measured and the results were compared to the model.

    The Mona Lisa Lasercom to the Moon from NGSLR demonstrates the potential of the SG Network beyond geodesy. The NASA news release was picked up by nearly all the major news outlets. Several members of the NGSLR team were co-authors of the paper which was published online in Optics Express.

    Read the paper in Optics Express
    Read the NASA news release
  • Dr. Henry Plotkin, visits NASA's Next Generation Satellite Laser Ranging (NGSLR) system12/2012 Retired NASA physicist, Dr. Henry Plotkin, visits NASA's Next Generation Satellite Laser Ranging (NGSLR) system in December 2012. As the former Head of the old Optical Systems Branch (Code 524) at NASA Goddard Space Flight Center, Dr. Plotkin led the development of the earliest NASA SLR systems. His team recorded the first laser returns from a retroreflector-equipped artificial satellite (Explorer 22B) almost 50 years ago on October 31, 1964. He is shown here with Jan McGarry in front of the NGSLR system.

    View larger image
  • Ignite GGOS!
    11/21/2012 The IGS and UNAVCO are sponsoring an evening reception on December 02, 2012 on behalf of the Global Geodetic Observing System (GGOS). A fun, educational, and humorous evening of short, fast-paced presentations will be given by people who are passionate about what they do. There will be plenty of appetizers and a cash bar.

    Ignite GGOS 2012!
    Sunday, December 2nd, at 7:00 pm
    The Westin San Francisco Market Street
    Metropolitan 1
    50 Third Street
    San Francisco, California

    Ignite is an O'Reilly Media concept meant to be fast-paced, creative, and outside-the-box of conventional conference presentations. Ignite GGOS promises to be a fun and light-hearted hour to stimulate your thinking with diverse visions for GGOS and beyond.

    For more information, please contact: IGS Central Bureau, Ignite Coordinator:
  • International Technical Laser Workshop 2012 (ITLW-12) 11/19/2012 The ILRS held an International Technical Laser Workshop 2012 (ITLW-12) on "Satellite, Lunar and Planetary Laser Ranging: characterizing the space segment" at the Frascati National Laboratories of the INFN-LNF, Frascati (Rome), Italy on November 5-9, 2012, in conjunction with a one-day Workshop on "ASI-INFN ETRUSCO-2 Project of Technological Development and Test of SLR Payloads for GNSS Satellites". The meeting focused on the laser ranging space segment including retroreflector arrays for Earth orbiting satellites and the moon, with special attention to the expanding role of ranging to GNSS and geosynchronous satellites. Topics also included receivers in space for time transfer experiments (T2L2), one-way ranging to lunar orbiters (LRO) and interplanetary spacecraft (MLA, MOLA), and data relay systems.
  • New ILRS web site released 10/09/2012 The ILRS Central Bureau is pleased to announce the implementation of a new design for the ILRS website, The redesign process has allowed for a review of the organization of the site and its contents, ensuring information is current and useful. Comments and suggestions are welcome and should be directed to the ILRS web team at We would like to acknowledge the efforts of the website development team (Lisa Lee, Mark Torrence, Lori Tyahla, and Carey Noll) as well as members of the Central Bureau and the ILRS community for their contributions to the site content.
  • Space Geodesy Request for Information
    08/30/2012 The National Aeronautics and Space Administration (NASA) is soliciting information to improve its understanding of the interest, capabilities, and Rough Order of Magnitude (ROM) estimates for planning the construction, deployment, and operation of the next generation Space Geodesy (SG) stations that will be part of the upcoming NASA’s Space Geodetic Network (SGN). NASA is considering the construction of up to ten new or upgraded stations that will contribute to the larger Global Geodetic System (GGOS).

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  • Staff Profile: Jan McGarry, Mathematician
    08/16/2012 Mathematician Jan McGarry discusses the science and history of Satellite Laser Ranging (SLR), her role in developing the Next Generation Satellite Laser Ranging system, and her career at NASA's Goddard Space Flight Center.

    Watch video
  • NGSLR Optical Bench Laboratory Build Status
    08/15/2012 The design and laboratory build of the new Optical Bench has been completed. Assembled at a GSFC Building 33 clean room laboratory, the new bench offers an improved optical layout, incorporates alignment lasers, and uses monitoring cameras for more efficient alignments. A beam profiler has been incorporated allowing verification of the transmit beam divergence and doubles as a means of monitoring the pointing of the laser. The new design now supports motorized optical mounts to enable automated operations. The Optical Bench was upgraded with a higher power, shorter pulse width laser for more robust daylight GPS ranging along with the use of high power coatings on the transmit optics to handle the extra energy. The original Optical Bench was designed for laser energies up to 350 microjoules while the new Optical Bench is designed to handle energies up to 3,000 microjoules. The laboratory build of the new Optical Bench allowed engineers to test the new layout and develop alignment procedures for the enhanced design. While the build was taking place in the laboratory, system development efforts were allowed to continue at the NGSLR. Completed in July, the new bench is in the process of being moved to the NGSLR. Pictures of the new bench undergoing the laboratory build are shown.

    View images
  • Time-lapse video of VLBI2010 Installation at GGAO
    08/14/2012 Time lapse video showing the construction of the VLBI2010 antenna at NASA Goddard Geophysical and Astronomical Observatory GGAO, September 15 through October 12, 2010.

    Watch video
  • NGSLR 2012 Summer Interns
    08/05/2012 SGP staff mentored eight interns during the summer of 2012.

    Visit 2012 Interns page
  • Staff Profile: Carey Noll, Computer Scientist
    08/02/2012 Computer scientist Carey Noll talks about her job as manager of the Crustal Dynamics Data Information System (CDDIS), the applications of her work for various space geodesy techniques such as GPS, and her career at NASA's Goddard Space Flight Center.

    Watch video
  • Staff Profile: Chopo Ma, Space Geodesist
    07/12/2012 Space geodesist Chopo Ma explains the science of Very Long Baseline Interferometry (VLBI): using radio emissions from distant galaxies to create a precise reference frame for the Earth.

    Watch video
  • "Sizing Up Earth" for iPad
    07/10/2012 Read an introduction to Space Geodesy using the NASA Visualization iPad app.

    Read more
    Download NASA Visualization iPad app
  • Staff Profile: Stephen Merkowitz, Project Manager
    07/05/2012 Project manager Stephen Merkowitz talks about his work with NASA's Space Geodesy Project, including a brief overview of the four fundamental techniques of space geodesy: GPS, VLBI, SLR, and DORIS.

    Watch video
  • NASA Explains Why Clocks Will Get an Extra Second on June 30
    06/29/2012 If the day seems a little longer than usual on Saturday, June 30, 2012, that's because it will be. An extra second, or "leap" second, will be added at midnight to account for the fact that it is taking Earth longer and longer to complete one full turn—a day—or, technically, a solar day.

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  • Using Quasars to Measure the Earth: A History of VLBI
    06/21/2012 VLBI, or Very Long Baseline Interferometry, is a technique that uses multiple radio telescopes to very precisely measure the Earth's orientation. It was originally invented back in the 1960s to take better pictures of quasars, but scientists soon found out that if you threw the process in reverse, you could measure how the ground beneath the telescopes moves around, how long days really are, and how the Earth wobbles on its axis as it revolves around the sun!

    Watch video
  • NGSLR Makes its First Successful Daylight Ranging to a GNSS Satellite
    04/30/2012 NGSLR made its first successful daylight ranging to a GNSS satellite (GLONASS-109) on April 2, 2012 at approximately 7pm EDT, about 30 minutes before sunset. The system obtained satellite returns immediately after laser turn-on. The satellite was tracked for an hour, down below 35 degrees elevation. The pass was strong enough for real-time signal processing to find much of the signal. A second daylight GNSS pass on GLONASS-115 was obtained on April 3, 2012 at appoximately 2pm EDT.

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  • NASA Response on Legacy Stations Submitted and Accepted
    03/26/2012 The The NASA response on legacy stations submitted to the GGOS Bureau for Networks and Communication Call for Participation was recently accepted.
  • NASA Pinning Down "Here" Better Than Ever
    02/23/2012 NASA is helping to lead an international effort to upgrade the four systems that supply crucial location information in pinpointing where "here" is.

    Watch Video
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  • VLBI2010 Demonstration with Full Configuration at GGAO
    01/20/2012 VLBI2010 successfully conducted 4-band fringe test and emonstrated antenna aperture efficiency, feed horn sensitivity, and backend data system components meet baseline VLBI2010 requirements.

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  • Installation of GNSS deep drilled brace monuments
    01/20/2012 The installation of GNSS deep drilled brace monuments at GGAO was completed. Multi-Constellation GNSS receivers, antennae/radomes, and supporting data collection computer have been installed at GGAO and are operating and actively collecting data. Both GNSS receivers are Delta-series units from Javad.

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