USSPACECOM Stops Publishing 2-line Element Sets for GPS Satellites
Tue, 30 Mar 1999 10:57:01 +0100

This was distributed on a GPS mailing list. In fact, I failed
several times in downloading GPS/Navstar tles from OIG.

Rainer  :(

>Around 5 March, the United States Space Command stopped releasing
>two-line orbital element sets for the GPS satellites.  These basic
>orbit descriptions are determined for all earth-orbiting satellites by
>USSPACECOM using various tracking facilities around the globe.  Although
>USSPACECOM withheld orbital information on some (maybe most) U.S. military
>satellites, the information on the GPS satellites has always been freely
>available (via NASA's Goddard Space Flight Center) until a few weeks ago.

>Today, I received confirmation from Maj. Mike Birmingham (USSPACECOM
>Public Affairs) that DoD has made a decision to stop publishing the
>orbital element sets for the GPS satellites (and, incidentally, the DMSP
>(Defense Meteorological Satellite Program) satellites) for security
>The GPS satellites are, apparently, now classified as "sensitive"
>It appears DoD has made this decision despite the fact that the GPS
>themselves transmit orbital information that is considerably more accurate
>than that provided by the two-line orbital elements (roughly 1-km
>and it is easy to convert the transmitted data into two-line format.
>According to Maj. Birmingham, the decision had nothing specifcally to do
>the current NATO activity.
> Richard B. Langley                            E-mail:
> Geodetic Research Laboratory                  Web:
> Dept. of Geodesy and Geomatics Engineering    Phone:    +1 506 453-5142
> University of New Brunswick                   Fax:      +1 506 453-4943
> Fredericton, N.B., Canada  E3B 5A3
>     Fredericton?  Where's that?  See: