RE: how useful are these old elsets?

Bjoern Gimle (b_gimle@algonet.se)
Tue, 14 Jan 1997 21:42:49 +0100 (MET)

>Ryan Rudnicki asked the following, regarding the
>many "old" elsets that appear in the *.n2l file:
>
....
>
>>Are these orbits stable 
>>enough that they don't need refreshing too often?  
....
Ted Molczan replied:
.......
>
>Ideally, I believe that ephemeris generators should include some means
>of estimating prediction uncertainty, like the one above, and perhaps 
>indicate whether or not an object manoeuvres, instead of simply discarding 
>old elements.
>
I agree with this ! Quicksat does a reasonable estimate of UNC in minutes,
and it uses an 'object dictionary' called 'Reference Magnitude File'.

All maneuvering objects could be designated by a 'flag character' in the
file, and that can be used to select (or de-select) objects to match your
observational interests.

My ideal is that more programs support a reference file,
preferably in a common format;
that SeeSatters can provide updates on new, decayed and identified objects;
and elset manager programs use the file to select elsets for storing /
prediction programs that can't use the file;
and help include the published updates, and produce guesswork
updates from elsets. 


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