X-Sympa-To: ids.analysis.forum Received: from hector.cls.fr (hector.cls.fr [62.161.32.9]) by hermes.cls.fr (8.9.3/8.9.3) with ESMTP id MAA11753 for ; Wed, 21 Feb 2007 12:48:05 GMT Received: by hector.cls.fr (Postfix) id F2ABE7165B; Wed, 21 Feb 2007 13:17:04 +0000 (GMT) Delivered-To: ids.analysis.forum@cls.fr Received: from cluster-e.mailcontrol.com (orange-102.cls.fr [62.161.32.13]) by hector.cls.fr (Postfix) with ESMTP id D10E730B03 for ; Wed, 21 Feb 2007 13:17:03 +0000 (GMT) Received: from smtp1.ign.fr (smtp1.ign.fr [192.134.133.226]) by rly13e.srv.mailcontrol.com (MailControl) with ESMTP id l1LDGuHv003174 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 21 Feb 2007 13:16:57 GMT Received: from pop.ign.fr (pop.ign.fr [172.16.255.1]) by smtp1.ign.fr (8.13.4/8.13.4/Debian-3sarge1) with ESMTP id l1LDGqim025141; Wed, 21 Feb 2007 14:16:54 +0100 Received: from [172.16.0.131] (rama.ign.fr [172.16.0.131]) by pop.ign.fr (Postfix) with ESMTP id 985643C4003; Wed, 21 Feb 2007 14:16:52 +0100 (CET) Mime-Version: 1.0 Message-Id: In-Reply-To: <200702211004.l1LA4EnX014623@proxy.gao.spb.ru> References: <200702211004.l1LA4EnX014623@proxy.gao.spb.ru> Date: Wed, 21 Feb 2007 14:17:20 +0100 To: ids.analysis.forum@cls.fr From: "H.Fagard" Subject: Re: [ids.analysis.forum] DORIS ground marks survey tie Cc: zmalkin@zmalkin.com Content-Type: text/plain; charset="iso-8859-1" ; format="flowed" Content-Transfer-Encoding: 8bit X-Mailcontrol-Inbound: 4wnd!s!p9LR4o+QFvM6fko6PYHaLGMlP X-Spam-Score: -2.1 X-Scanned-By: MailControl A-07-06-90 (www.mailcontrol.com) on 10.69.0.123 X-Validation-by: laurent.soudarin@cls.fr Dear Zinovy, dear all, At 13:05 +0300 21/02/07, Zinovy Malkin wrote: >Usually, e.g. for SLR and GPS we prefer to refer the >computed coordinates to the ground mark Yes this is the "normal" and much better convention. Unfortunately this was not initially chosen for DORIS, and we have to live with that. Moreover, the chosen "DORIS reference point" (i.e. the point whose coordinates are published) for the second generation antennas (Starec type) was not a good choice either: it is neither the point on which positioning measurements are actually carried out (the 2 GHz phase centre), nor the easiest one to accurately survey (the base of the antenna). Therefore we (at IGN) need to take special precautions when installing and surveying such antennas, in order to take into account geometry defects of the antennas (which were noticed at several sites). Best regards, Hervé Cliquez sur l'url suivante https://www.mailcontrol.com/sr/0l8!tflf1emlYj5oy3+pRtGWNfd1r8+!GK39A19NyWJ1bW+8!L+RvAnr9zHWD!OJ!qQPfBjdr5sWSGOLXEYrUzYYPM!sy7S4Gdrae7G9DtSv7ESFEkWBHJ4v016CwbnVULCLNqxuq9g8r!VC74E1lKxP3ajankBcUS8WsUnUSQL4moVI!NKlmDSbd0tXGRckEICyl8YTBaAgtJvfBGivJLPmgUSJxQ9e si ce message est indésirable (pourriel).