Bum elements?

Matson, Robert (ROBERT.D.MATSON@cpmx.saic.com)
Mon, 9 Nov 1998 19:29:39 -0800

Hi Mark and list,

Something suspicious may be going on with the most recent
MOLCZAN.TLE file.  I was out looking for TRMM Monday
evening, Nov. 9th, but did not see it.  I had been warned by
Ralph McConahy that it had not appeared when expected for
a near-zenith pass on Sunday night, so he thought it might
have recently maneuvered.  That being the case, I assumed
that it would have been boosted to a higher orbit, and thus it
would have come late.  I watched for an extra 5 minutes but
saw nothing.  This satellite is too bright to be missed, so
something is up.  The elements were only about 5 days old,
so I couldn't imagine it being more than 5 minutes late.

Later I was looking for Cosmos 2347.  Fortunately I was looking
early -- it came a full minute early.  Almost EXACTLY one minute.
This was very suspect, since the satellite is not in a particularly
low orbit, and again the elements were quite fresh.

When I tried ALLDAT.TLE instead, the observation matched
exactly for C2347.  Surprising, considering the epochs only differ
by one day.  Curious at this discovery, I decided to check TRMM.
The prediction changed by exactly 90 seconds EARLIER.  This I
quite possibly could have missed.

So the question is:  was this just a fluke or did OIG put out some
bum elements?  Here are the two sets for the above objects:

TRMM - Molczan   5.0  4.0  0.0  3.5 v
1 25063U 97074A   98309.17943830 -.00177486  00000-0 -12204-2 0  4460
2 25063  34.9946 244.7133 0003701 231.5039 128.5339 15.74079704 53969
TRMM - ALLDAT    5.0  4.0  0.0  3.5 v
1 25063U 97074A   98310.19422543 -.00120781 +00000-0 -83243-3 0 04500
2 25063 034.9951 237.8204 0001159 078.8231 281.2891 15.73880683054122

C2347 - Molczan  8.0  3.0  0.0  3.5 v
1 25088U 97079A   98308.85156995 -.00015501  00000-0 -25075-3 0  4611
2 25088  65.0213 184.9327 0010939 281.9873  78.0048 15.52011176 51301
C2347 - ALLDAT   8.0  3.0  0.0  3.5 v
1 25088U 97079A   98310.20472446 +.00021826 +00000-0 +36214-3 0 04763
2 25088 065.0214 180.3560 0010780 280.8521 079.1407 15.52077229051518

Cheers,

Rob