Subject: TOPEX/DORIS POD - large residuals detected for 2004-267=SEP-23-2004
From: Pascal Willis <[email-masked]>
To: IDS_Analysis_Forum <[email-masked]>
Date: Wed, 20 Oct 2004 09:16:12 -0700

Hi everybody,

I just detected a possible problem when processing the recently 
available DORIS/TOPEX data file (topdata443.001.Z). I thought it 
could be a good idea to start some discussion on this using the new 
IDS Analysis forum. So let's give it a try.

It seems that the TOPEX/DORIS residuals for a specific day (2004:267 
= 23-SEP-2004) are quite high (0.7 mm/s instead of the regular 0.45 
mm/s).

I did a few tests here but I am still not able to identify the exact 
nature of the problem. The estimated drag parameters seems to go far 
away from usual. Maybe the problem could be less visible in longer 
arcs.

Do you see anything special in TOPEX/DORIS POD around this specific day?

Do you understand why?

Thanks in advance
Pascal

NB: When I restrict to 24-hour arc and estimate as well the station 
coordinates with the orbit, I get good residuals but bad results for 
the station coordinates.
-- 
Pascal Willis
Jet Propulsion Laboratory, MS 238-646     Ph : 1-818-393-4748
4800 Oak Grove Drive                      FAX: 1-818-393-4965
Pasadena CA 91109                         Em : [email-masked]