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Photo of Jim LongPassing of James Leroy Long (1955 - 2019)Release Date: 09/30/2019The Space Geodesy Project and the ILRS community is mourning the loss of our dear friend and colleague James Leroy Long who passed away on September 21, 2019 from prostate cancer complications.

Jim was a leader and essential contributor to the nation's space geodesy programs over the past 40 years. Jim began his career in 1978 as a Commissioned Officer within the US Department of Commerce NOAA Corps. For two years, Jim was the Party Chief for the transportable 5-meter antenna system collecting Very Long Baseline Interferometry (VLBI) data in support of the NASA Crustal Dynamics Program and the NOAA National Crustal Motion Network. These measurements led to the first measurements of continental drift. Jim also spent several years on mobile field duty for the U.S. Coast & Geodetic Survey performing precise horizontal control surveys and special project surveys.

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2019 Technical Workshop logo2019 ILRS Technical WorkshopRelease Date: 08/06/2019The 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.

The ILRS is looking forward to seeing you all in Stuttgart!

Galileo satelliteGNSS Tracking StrategyRelease Date: 08/01/2019 The ILRS has been working with the IGS and other interested parties to settle on a GNSS tracking strategy that would satisfy both mission and user requirements. For some applications, users want denser tracking on a few satellites. For other applications, users want some tracking on the full complex of GNSS satellites, even if that tracking is sparse. In addition, there are also requests for focused campaigns, in particular, for tracking GNSS satellites while going through Earth shadow to study the effects of radiation pressure. We presently have over 60 GNSS satellites (GLONASS, Galileo, BeiDou) on the ILRS roster. More will be added in the near future. The total could reach nearly 100 when GPS is added in the 2024 timeframe.

The strategy that the ILRS has agreed to implement is the following:

  • GNSS tracking will continue to be prioritized with the other ILRS satellites by the standard ILRS priority scheme (by altitude and inclination);
  • Four GNSS satellites will be identified by each constellation (Galileo, GLONASS, and BeiDou) for intensive tracking, with three sectors (at least 2 normal points each) spaced widely apart over the pass. If stations cannot obtain three sectors they should try to get two sectors. These four satellites per constellation would be selected by the constellation and would have the highest priority among the GNSS satellites.
  • All of the remaining GNSS satellites would be tracked by the stations on an as time available basis; selection of targets should be determined by the stations for data yield, but stations are asked to try to diversify among all three constellations because we need some data on all three.
  • There may be some special tracking periods (e.g. satellite eclipses, etc.) that may need other scheduling.
The agreed high priority GNSS satellites are:

  • BeiDou3-M2, 3-M3, 3-M9, and 3-M10
  • Galileo-102, -202, -209, -210
  • GLONASS-131, -134, -138, and -139
The ILRS asks that you implement this new priority strategy in your tracking operation, by August 15, 2019. Please contact the ILRS CB if you have any questions.

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