RE: NavSpaSur

Josh R. Williams (
Thu, 4 Jan 1996 22:35:07 -0500 (EST)

I stand corrected, I was told by someone that it is a network of 
satellites which use radar to track the Satellites, thanks for the 
accurate information...

|          Josh R. Williams          |      ** JRW Satellite Page **       |
|     E-Mail:      | URL: |
|          Location: Monroe, Michigan - United States of America           |
|        Latitude: 41 deg 59' 29" N -- Longitude: 83 deg 27' 41" W         |

On Thu, 4 Jan 1996, Ted Molczan wrote:

> Josh Williams asked:
> >Does anyone know any of the NORAD numbers for the NavSpaSur Satellites? I 
> >would like to track them but information is VERY hard to come by, also TS 
> >Kelso has told me that the project is NOT classfied, and that confused me 
> >even more. Maybe the satellites are not named after the project, which 
> >maybe the problem here...
> NavSpaSur stands for Naval Space Surveillance System.
> It is not a satellite system. It is an Earth-based radar
> interferometer system, used to detect and track satellites.
> It consists of three stations which transmit a powerful
> 217 MHz signal narrow fan-beam of radio waves across the
> southern U.S.A. The fan can be thought of as a fence of
> radio waves. When satellites cross through it, they reflect
> some of the radio waves, which are then received by several
> of six receivers across the southern U.S.A. The motion of
> a satellite causes the reflected radio waves to be Doppler-
> shifted. The amount of the Doppler shift will be different
> for each receiving site because the relative velocity of
> the satellite will be different for each site. By analyzing
> a sufficient number of near-simultaneous Doppler shifted
> reflections, the orbital elements of the satellite can be
> determined.
> I know at least one radio amateur in the southern U.S.A. who
> has received the reflections. In principle, hobbyists could
> make use of the NavSpaSur system, if they could build their
> own network of receivers and data reduction/analysis system.
> What little I know about this comes from Desmond King-Hele's
> book, Observing Earth Satellites, ISBN 0 333 33041 2.
> bye for now