X-Sympa-To: ids.analysis.forum Received: from hector.cls.fr (osis.cls.fr [62.161.32.21]) by hermes.cls.fr (8.9.3/8.9.3) with ESMTP id SAA10986 for ; Wed, 20 Oct 2004 18:21:02 +0200 Received: by hector.cls.fr (Postfix) id 56D0EE410B; Wed, 20 Oct 2004 16:21:01 +0000 (GMT) Delivered-To: ids.analysis.forum@cls.fr Received: from eis-msg-012.jpl.nasa.gov (orange-102.cls.fr [62.161.32.13]) by hector.cls.fr (Postfix) with ESMTP id 7E6511543AB for ; Wed, 20 Oct 2004 16:20:59 +0000 (GMT) Received: from [128.149.70.153] (mac01120073755.jpl.nasa.gov [128.149.70.153]) by eis-msg-012.jpl.nasa.gov (8.12.10/8.12.10) with ESMTP id i9KGKu1D005566 for ; Wed, 20 Oct 2004 09:20:57 -0700 (PDT) Mime-Version: 1.0 X-Sender: pwillis@mail.jpl.nasa.gov Message-Id: Date: Wed, 20 Oct 2004 09:16:12 -0700 To: IDS_Analysis_Forum From: Pascal Willis Subject: TOPEX/DORIS POD - large residuals detected for 2004-267=SEP-23-2004 Content-Type: multipart/alternative; boundary="============_-1113833520==_ma============" X-Validation-by: feissel@ensg.ign.fr --============_-1113833520==_ma============ Content-Type: text/plain; charset="us-ascii" ; format="flowed" 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 : Pascal.R.Willis@jpl.nasa.gov --============_-1113833520==_ma============ Content-Type: text/html; charset="us-ascii" TOPEX/DORIS POD - large residuals detected for 2004-267=SE
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 : Pascal.R.Willis@jpl.nasa.gov
--============_-1113833520==_ma============--