To: igsmail@igscb.jpl.nasa.gov Subject: [IGSMAIL-5986]: AGU2009 Session G12: Challenges and Opportunities in Combining Multiple GNSS Observations Message-ID: From: Tim.Springer@esa.int Date: Wed, 19 Aug 2009 13:50:58 +0200 Content-Type: text/plain; charset="us-ascii" Sender: owner-igsmail Precedence: bulk ****************************************************************************** IGS Electronic Mail 19 Aug 04:51:27 PDT 2009 Message Number 5986 ****************************************************************************** Author: Tim Springer and Yoaz Bar-Sever Dear IGS Colleagues, We would like to draw your attention to our GNSS session (G12) at the AGU2009 meeting. The detailed session description is attached below. AGU abstract deadline is: September 3 Many greetings, Tim and Yoaz G12: Challenges and Opportunities in Combining Multiple GNSS Observations The availability of modernized GPS, a revitalized GLONASS, and the upcoming Compass and Galileo will offer many challenges but also exciting opportunities in the next decade. Mixing different GNSS today brings about significant complications like intersystem biases and because of different modulations, e.g. CDMA for GPS versus FDMA for GLONASS, also frequency dependent biases. The addition of new signals on existing frequencies as well as additional frequencies will further complicate matters. Today we are already suffering issues with this with GPS alone. The new available civil code measurements on the L2 frequency has lead to an inhomogeneous set of observations from different receivers. Some receivers now deliver only C1 and C2 whereas others provide only P1 and P2. The combination of observations of such receivers is problematic because of the biases present in each of these observations. Thinking about the future with Galileo offering 5 different measurement types on E1, 9 different measurement types on E5, and 5 different measurement types on E6 (see RINEX 3.00) the myriad of different observation combinations and biases becomes mind-boggling! And things get even more complicated if we think about GLONASS moving from FDMA to CDMA and the new Compass system. Despite all these challenges we are convinced that the new and improved signals, as well as the new and additional satellites in different orbit configurations do present some very exciting opportunities. This is especially true considering that the planned GNSS systems promise to increase the number of satellites by a factor of 4 and to improve the accuracy of the (code) measurements by a factor of 10 (from 1 to 0.1 meters). With this session we would like to invite presentations addressing not only the challenges but also presentations highlighting the opportunities offered by the new signals and systems. We therefore would appreciate contributions which focus on ensuring that we will in fact be able to combine the observations from all different systems observed by many different receivers. Here contributions from the hard- and soft-ware receiver side are especially welcome. Furthermore we solicit contributions focusing on the scientific opportunities offered by true GNSS solutions, e.g. GPS + GLONASS, COMPASS, and/or Galileo, both today as well as in the (near) future.