• Laser ranging to the moon
    Laser Ranging to the Moon
    NGSLR, located at NASA GSFC's Goddard Geophysical and Astronomical
    Observatory (GGAO),is shown ranging to the Lunar Reconnaissance Orbiter (LRO)
    orbiting the Moon. The LRO Laser Ranging (LR) system enables the spacecraft
    to achieve its precision orbit determination requirement.
  • antenna
    VGOS, located at NASA GSFC's Goddard
    Geophysical and Astronomical Observatory
    (GGAO), is the next generation of
    geodetic VLBI systems currently
    under development.
  • Monument brace
    Drilled Brace Monument for GNSS Antenna
    The newly installed drilled brace monument for the
    Global Navigation Satellite System (GNSS) antenna at
    NASA GSFC's Goddard Geophysical and Astronomical
    Observatory (GGAO). The multi-GNSS-capable
    receiver will track signals from several GNSS including
    GPS, GLONASS, and Galileo.
    DORIS Antenna
    The Doppler Orbitography and Radio-positioning Integrated
    by Satellite (DORIS) antenna located at NASA GSFC's Goddard
    Geophysical and Astronomical Observatory (GGAO) tracks
    satellites equipped with DORIS beacons; NGSLR can be seen
    in the background.

Latest news

Space Geodesy helps track effects of global change
Laser ranging at night at NASAA new article in the September issue of the Smithsonian's Air & Space magazine describes how space geodesy is tracking the effects of global change down to the millimeter. Several NASA Space Geodesy Project researchers were interviewed for the article including Stephen Merkowitz, Jan McGarry, and Frank Lemoine.

Read the article in Air & Space Magazine.

SGP officially takes ownership of the GGAO SGSLR shelter
The SGSLR shelter at GGAOThe GGAO SGSLR shelter official inspection took place the morning of Tuesday July 30th. The official punch list for the inside was generated. Participating in this walk through were the Goddard Project Manager for the construction, Quality Assurance, Safety, the Construction team and SGP personnel (Long, McGarry, Donovan and Nelson). After the inspection, SGP officially took ownership of the shelter which is now Goddard building 228. The exterior walk through will occur after the outside stairs are complete.

See more photos on the SGSLR @ GGAO blog.

2019 ILRS Technical Workshop
2019 ILRS Workshop BannerThe 2019 ILRS Technical Workshop will take place in Stuttgart, Germany, October 21-25. If you plan to attend, please register by August 15 (next Thursday) on the workshop website:


If you have any trouble registering, please send an email to ilrs.workshop@dlr.de. If you plan to present at the workshop, we ask that you also upload your abstract as soon as possible so we can commence planning the program. We are looking forward to seeing you all in Stuttgart!

Reflectors placed on the moon by Apollo 11 astronauts 50 years ago continue to provide fresh lunar laser ranging data
retroreflectors on the surface of the moonFifty years ago, Neil Armstrong, Buzz Aldrin and Michael Collins left behind arrays of prisms that reflect light back toward its source; the Apollo 14 and 15 astronauts also did so. Four telescopes at observatories in New Mexico, France, Italy and Germany fire lasers at them, measuring the time that it takes for a laser pulse to bounce off the reflectors and return to Earth. This allows the distance to be measured to within a fraction of an inch (a few millimeters), and scientists at the Jet Propulsion Laboratory analyze the results. Lunar laser ranging measurements have deepened our understanding of the dance between the Moon and Earth.


Michael Lefebvre, French pioneer and major actor in satellite geodesy, passes away
retroreflectors on the surface of the moonMichel Lefebvre has passed away at his home on July 21, 2019 after a long illness. He was one of the French pioneers and a major actor in satellite geodesy. He contributed enormously to training the researchers and engineers of today in this discipline, at the time of the formation of GRGS (Groupe de Recherche de Geodesie Spatiale), which resulted from the cooperation of research teams at CNES (Michele’s team), Meudon Observatory and others. This was also the time of international satellite observing campaigns (ISAGEX, Trapol, Medoc, etc.) in which Michel was deeply involved.


Journal of Geodesy Special Issue on Laser Ranging
Cover of the Journal of GeodesySeveral peer-reviewed Journal of Geodesy articles were recently published online at the journal site. These are all part of the Special Issue on Laser Ranging which is preparation. Several more articles are in the review process and upon completion the printed version will be published.

In the meantime we invite you to peruse all of these with the latest information on Laser Ranging and the ILRS.

Introductory and Refresher Course on Satellite and Lunar Laser Ranging
Haleakala siteThe ILRS has scheduled a one-day introductory course to give non-practitioners in SLR an opportunity to broaden their knowledge about laser ranging to Earth-orbiting satellites and the Moon. The course will also provide those with some experience in the field an opportunity to refresh and strengthen their knowledge and increase their appreciation of this powerful measurement technique that supports geoscience and applications. The course is scheduled for Sunday, October 20, 2019, in Stuttgart, Germany, just prior to the 2019 ILRS Technical Workshop. The program for this one-day "SLR School" is available.

Talks will be given in a tutorial format, with time for questions and discussion. Interested parties can attend the school with or without participating in the Workshop. Attendees will be charged an entrance fee of 30 Euros to cover lunch and breaks.

Tutorials will differ in length depending on the topic, but each session should leave ample time for questions and discussion. Seminars will be given at the level of a non-expert, recognizing that we expect people to attend who are not currently working in the field, but are curious, as well as people who are newly involved in laser ranging, but need to broadening their current level of understanding.

The one-day SLR School will be a great way for attendees to get an overview of an important component of the space geodesy measurement constellation. Please see the attached PDF for the topics to be covered in the program. Participants in the 2019 ILRS Technical Workshop can indicate their plans to attend the SLR School during registration (see http://dlr.de/ilrs2019). Those wishing to attend only the SLR School should contact the workshop’s local organizing committee (ilrs.workshop@dlr.de); arrangements are being made for payment of the one-day fee.

This one-day event is an opportunity for participants to get an overall view of satellite laser ranging and is the first time that such a school has been offered. The school will be held at the:

Pullman Stuttgart Fontana Hotel
Vollmoellerstraße 5, 70563 Stuttgart, Germany

More Information on hotels, transportation, etc., is available on the workshop website at: http://dlr.de/ilrs2019.

Results of The National Geodetic Survey's local tie survey at the NSGN Haleakala site posted
Haleakala siteThe National Geodetic Survey posted the results of their local tie survey at the NSGN Haleakala site on Maui, Hawaii. Vectors were measured between the SLR and GNSS station and ground marks to support the International Terrestrial Reference Frame and NGS's Foundation CORS program. The survey results, report, and SINEX file are available at the NGS website.

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