To: igsmail@igscb.jpl.nasa.gov Subject: [IGSMAIL-5835]: ESOC Analysis Changes Message-ID: From: Tim.Springer@esa.int Date: Fri, 26 Sep 2008 17:42:45 +0200 Content-Type: text/plain; charset="us-ascii" Sender: owner-igsmail Precedence: bulk ****************************************************************************** IGS Electronic Mail 26 Sep 08:43:00 PDT 2008 Message Number 5835 ****************************************************************************** Author: Tim Springer Dear IGS Colleagues, In the last two weeks we have made a couple of small changes to our IGS Final analysis. One change is that we switched to a new release of our Napeos software which we call version 3.1. Amongst others, this version enables us a better handling of the biases observed between the GPS and GLONASS observations in the GNSS receivers. We can now export the estimated biases to our normal equations and stack them over the full week and consequently eliminate them before generating our SINEX file. In this way we are now able to generate a proper GNSS SINEX file which can be used in the IGS SINEX combination. A second change is that starting with this weeks submission we have added a large set of non-IGS, but GNSS(!!), stations to our processing. We were "forced" to include these non-IGS sites because the IGS tracking network provides very poor tracking of the GLONASS satellites and this has a significant (negative!!) impact on our products. The added GNSS stations are locations where the IGS network provides very little, or even no, GNSS tracking. Amongst these stations are 8 CORS stations, many thanks to Giovanni Sella for making them available and to our BKG colleagues for downloading the data and making it available on their GLONASS data archive. These CORS stations significantly improve the GLONASS tracking over North-America. An other important addition are a set of 7 Brasilian stations. These stations are in the process of becoming IGS stations and should soon be. Again, we are able to access this data thanks to our BKG colleagues who are generating the data of these stations from their real-time NTRIP streams. In order to not "drop" any IGS reference frame stations we increased the number of stations in our processing from 100 to 110. Starting with the submission of this week we now submit a complete set of GNSS products, i.e., orbits, clocks, summary, but also the clock and sinex files are now submitted to the IGS data centers. It is our intention that within the next couple of weeks we will terminate our GPS-only solution and only produce and submit our true GNSS products to the IGS (we will of course coordinate and test this change with the different combination centers before going "life" with it). The users of the ESOC products are advised the have a look at our "esx" line of products to see if your software is able to ingest these GNSS solutions! With the launch of 3 new GLONASS satellites yesterday and 3 more scheduled for launch in December the GLONASS constellation is nearing FOC status. We hope that the IGS network follows this GLONASS evolution by putting up more GNSS sites, since there are still significant "holes" in the GLONASS part of the IGS tracking network. Many greetings, Tim Springer --------------------- Tim Springer Navigation Support Office, OPS-GN (nng.esoc.esa.de) European Space Operations Centre Robert Bosch Strasse 5 64293 Darmstadt Germany Tel: +49-6151-90-2029 Fax: +49-6151-90-3129