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 QAA08662 for ; Tue, 30 Aug 2005 16:10:38 +0200 Received: by hector.cls.fr (Postfix) id 423AD116832; Tue, 30 Aug 2005 14:10:37 +0000 (GMT) Delivered-To: ids.analysis.forum@cls.fr Received: from rly06d.srv.mailcontrol.com (orange-103.cls.fr [62.161.32.14]) by hector.cls.fr (Postfix) with ESMTP id E3E0D99D10 for ; Tue, 30 Aug 2005 14:10:35 +0000 (GMT) Received: from chappe.cnes.fr (chappe.cnes.fr [132.149.22.2]) by rly06d.srv.mailcontrol.com (MailControl) with ESMTP id j7UEARAM025820 for ; Tue, 30 Aug 2005 15:10:27 +0100 Received: from cnes.fr by chappe.cnes.fr id j7UEARS10074; Tue, 30 Aug 2005 16:10:28 +0200 (MET DST) Message-Id: <200508301410.j7UEARS10074@cnes.fr> Date: Tue, 30 Aug 2005 14:10:26 +0000 (GMT) From: jean-michel lemoine -grgs-61332 Reply-To: jean-michel lemoine -grgs-61332 Subject: Re: [ids.analysis.forum] Consider using Eccentricities for DORIS processing To: ids.analysis.forum@cls.fr MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="Cry_of_Hounds_894_000" X-Loop-Check: X-Mailcontrol-Inbound: DJCAEaTMxvBuMdaY9TbUIwpHfdsMjUpSWNkuoo60Zso= X-Spam-Score: -0.7 X-Scanned-By: MailControl A-05-01-05 (www.mailcontrol.com) X-Validation-by: feissel@ensg.ign.fr This is a multi-part message in MIME format... --Cry_of_Hounds_894_000 Content-Type: TEXT/plain; charset=us-ascii Content-MD5: xdTqJyfQ0Cqet1tJXtFd5w== Content-Disposition: inline I fully agree with John's comments. The use of eccentricities has been implemented for a long time in the CNES/GRGS stations file, since we use a unified format for all types of stations (GPS, DORIS, VLBI, LLR, SLR, PRARE and even optical). Please find attached an example of this file in the case of the DORIS station of Manila. Best regards, Jean-Michel Lemoine ______________________________________________________________________ Jean-Michel Lemoine CNES/GRGS (DCT/SI/GS) BPI 3200 18, avenue Edouard Belin 31401 Toulouse Cedex 4 France Mail : Jean-Michel.Lemoine@cnes.fr Phone : (33-5)/(05)-61-33-29-73 Fax : (33-5)/(05)-61-25-30-98 ---------------------------------------------------------------------- > X-Authentication-Warning: hermes.cls.fr: sympa set sender to ids.analysis.forum-owner@cls.fr using -f > X-Sympa-To: ids.analysis.forum > Delivered-To: ids.analysis.forum@cls.fr > Mime-Version: 1.0 > Date: Sun, 7 Aug 2005 21:32:03 -0500 > To: ids.analysis.forum@cls.fr > From: "John C. Ries" > X-Virus-Scanned: amavisd-new at csr.utexas.edu > X-Mailcontrol-Inbound: c!PzNVdyE6pAgYrdZN4HGLIOLgW8bYa616COtuSiUsY= > X-Scanned-By: MailControl A-05-01-05 (www.mailcontrol.com) > X-Validation-by: laurent.soudarin@cls.fr > X-Loop: ids.analysis.forum@cls.fr > X-no-archive: yes > List-Id: > List-Help: > List-Subscribe: > List-Unsubscribe: > List-Post: > List-Owner: > List-Archive: > Subject: [ids.analysis.forum] Consider using Eccentricities for DORIS processing > X-Spam-Checker-Version: SpamAssassin 3.0.4 (2005-06-05) on surcouf.cnes.fr > X-Spam-Level: > X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00 bayes=0.0000 autolearn=ham version=3.0.4 > > Dear Colleagues, > > In DORISMail 395, Herve provided this information: > > >Here is a summary of the different positions of the 2 GHz phase > >center, on which the DORIS positionning measurements are actually > >carried out: > > > >Time period East offset North offset > >26 Feb 2003 - Oct 2004 0 0 (ref. position) > >4 Oct 2004 - 29 Jun 2005 0.018 m 0.066 m (loose foot) > >30 Jun 2005 --> 0.007 m -0.003 m > > (new position) > > This prompts the question regarding how to best implement this kind > of information in the DORIS processing. I note that this is exactly > the kind of known offsets that the use of "eccentricities" is > designed to handle. These are common in SLR processing, so that many > occupations of the same site are rigorously tied together without the > need for breaks in the time series (unnecessarily weakening the > solutions). > > The alternatives are to simply live with the errors, for POD > applications, or to create a sequence of artificial site names (MAN1, > MAN2, etc), each with its own position vector. This inflates the set > of network coordinates for no useful purpose (as long as the > eccentricity is indeed know precisely). > > My recommendation would be to consider the creation of a set of > eccentricities, just as maintained for SLR, for sites where there are > known shifts or offsets and where the data continues to have the same > identifier. However, I don't know if the use of eccentricities is > common for those people processing DORIS data. > > We do not need to sort this out immediately, but at some point, we > should consider what sort of recommendation would be best. I suspect > we will need to be able to handle similar situations at other > locations. > > Best regards, > John > > > --Cry_of_Hounds_894_000 Content-Type: TEXT/plain; name="CNES_GRGS_station_format.Manila.txt"; charset=us-ascii; x-unix-mode=0640 Content-Description: CNES_GRGS_station_format.Manila.txt Content-MD5: MDg5M1jfeSku9jbXg3DNVA== Content-Disposition: inline station type site X (m) sig. Y (m) sig. Z (m) sig. Xp (m/an) Yp (m/an) Zp (m/an) ref.date plate origin* ecc. sig. ecc. sig. ecc. sig. occupation: start / end 22006 S001 Manille -3184357.591 ~0.010 5291042.203 ~0.009 1590419.468 ~0.005 0.0287 ~.0049 0.0130 ~.0042 0.0011 ~.0025 010197 EURA i00i00 22006 dorb MANA -0.255 ~0.000 0.423 ~0.000 0.128 ~0.000 040491 240203 22006 S002 Manille -3184355.140 ~0.010 5291043.770 ~0.009 1590420.080 ~0.005 0.0287 ~.0049 0.0130 ~.0042 0.0011 ~.0025 010197 EURA i00i00 22006 dloc MANB -0.243 ~0.000 0.404 ~0.000 0.122 ~0.000 260203 031004 22006 dloc MANB -0.250 0.000 0.380 0.000 0.186 0.000 041004 290605 22006 dloc MANB -0.249 0.000 0.401 0.000 0.119 0.000 300605 * : origin of information for position/velocity (i00 = ITRF2000) --Cry_of_Hounds_894_000--