Date: Mon, 16 Oct 2006 08:50:30 +0200 (CEST) From: gend@gfz-potsdam.de To: IGSmail Subject: [IGSMAIL-5440]: IGS Switch to new antenna model - a few remarks Message-ID: Content-Type: text/plain; charset="us-ascii" Sender: owner-igsmail Precedence: bulk ****************************************************************************** IGS Electronic Mail 15 Oct 23:50:41 PDT 2006 Message Number 5440 ****************************************************************************** Author: Gerd Gendt Dear colleagues, I would like to clarify the items raised for the new antenna model. Precise Point Positioning with IGS Products: Of course, to get the highest quality station positions with PPP the compatibel ANTEX file has to be used. Nevertheless, we have done some tests to see what the station position errors would be if the user has an old software and can only implement from the igs05.atx the satellite offsets as well as the receiver offsets and elevation dependent PCVs (i.e. ignoring the satellite antenna nadir dependence and the azimuthal dependence for the receivers). In this case one gets a scale error of about 0.8 ppb and translation errors of smaller than 0.5 mm. The position errors are site dependent (antenna depedent) and amount to +- 5 mm in the heights (in addition th the scale) and sub-mm in N and E. (see attached paper, which will soon be published in the proceedings of the IGS 2006 Workshop in Darmstadt). ANTEX file name in SP3: In the SP3 file there is not enough room to code all the necessary information one would like to see there. Therefore it was decided to shorten the name of the ANTEX file to its base name part, i.e. instead of igs05_1390 only igs05 (base name) (the general name is igsYY_WWWW.atx; YY year, WWWW - GSPWeek). For updating one realization, e.g. igs05, the corresponding GPSWeek is added to the filename. The basic rule is, however, that existing calibrations in the ANTEX realization must be fixed and can never be changed (see IGSMAIL-5272,19 Dec 2005). By this rule, even for older products, always the latest ANTEX file can be used, i.e. one has not to identify the ANTEX for a corresponding date. Changes are only allowed with a new realization, e.g. igs07. Those new realizations are only planned with a new full reprocessing of all historical data with the provision of a complete new set of products. This way the user will again have compatible products for the whole history. To ease the retrieval of the latest file the IGS will consider to set a link from igs05.atx to the latest realization. Best regards Gerd Gendt ****************************************************************************** * Gerd Gendt * * _/_/_/ _/_/_/_/_/_/ GeoForschungsZentrum * * _/ _/ _/ Department Geodesy and Remote Sensing * * _/ _/_/ _/_/ _/ Telegrafenberg A17 * * _/ _/ _/ _/ D-14473 Potsdam , GERMANY * * _/_/_/ _/ _/_/_/ Phone : ++49 331 288 1114 Fax :++49 331 288 1759 * * E-Mail: gendt@gfz-potsdam.de * * IGS GFZ AC : AFTP://ftp.gfz-potsdam.de/pub/igsprod * * http://www.gfz-potsdam.de/igs * * IGS Analysis Coord.: AFTP://ftp.gfz-potsdam.de/pub/igsacc * * http://www.gfz-potsdam.de/igsacc * ****************************************************************************** [demime 1.01d removed an attachment of type APPLICATION/zip which had a name of paper.zip]