Mon, 8 Jan 1996 01:12:07 -0500

Leo Barhorst wrote:

>Jim Varney misinterpeted my qoutation of King-Hele !
>K-H stated that if you use ONLY th obs from NavSpaSur and NO obs from other 
>sources you have the possibility of bias. 
>Thank you for the other info on USSPACECOM.

You are right, King-Hele did not say that USSPACECOM only uses NAVSPASUR
data when generating elements... please forgive me, Leo :)

Here's another excerpt from Major P.A. Jackson's paper which may be of

"The most essential step is space surveillance is to detect man-made objects
during launch, before they enter space.  This is the most common way that
objects are found and entered into the satellite catalog.

Space launches are initially detected before they enter space by the Satellite
Early Warning System, a constellation of satellites in geosynchronous orbit.

With initial launch detection information, the ground-based sensor network is
directed by the SSC to locate the new launch and all of its pieces.  The
sensor tracking data is then used to update the SSC element set database.
When the element sets are associated with the launch event, the launched objects
are cataloged.

Another significant way for objects to enter the catalog is when a satellite
breaks up into many smaller pieces.  When an object breaks up, the cloud of
pieces is often found by the large search patterns maintained by certain
ground-based sensors.  Sensors such as NAVSPASUR, Eglin [AFB, Florida - jv],
and Cavalier [North Dakota - jv] keep large search fences up at all times.
Administratively, the largest piece of the breakup maintains the satellite
catalog name given when the object was initially correlated to a launch.  The
rest of the pieces are cataloged with new international designator suffixes,
beginning from the last cataloged piece from the launch... 

Presently, USSPACECOM is not required to track and maintain orbit predictions 
on small debris (objects less than 10 cm)."

Good Passes,


Jim Varney          |  121^ 23' 54" W,  38^ 27' 28" N   |     Sacramento, CA
Civil Engineer      |            Elev. 20 ft.           |