From oliver.montenbruck at dlr.de Mon Feb 24 10:04:07 2014 From: oliver.montenbruck at dlr.de (Oliver Montenbruck) Date: Mon, 24 Feb 2014 19:04:07 +0100 Subject: [IGSMAIL-6868] New MGEX Multi-GNSS DCB Product Message-ID: <530B8997.7040908@dlr.de> Dear colleagues, with this mail, we would like to offer a new product for multi-GNSS differential code biases (DCBs) to IGS users. Proper knowledge of differential code biases is essential in many navigation applications as well as non-navigation applications such as ionospheric analysis and time transfer. With the plethora of new signals offered by modernized and new GNSSs, the need for a comprehensive multi-GNSS DCB product arises. As part of the IGS Multi-GNSS Experiment (MGEX) an effort has been made to derive DCBs for all available signals of GPS, GLONASS, Galileo, and BeiDou from ionosphere-corrected pseudorange differences. A zero-mean condition for each constellation is applied to separate satellite and station DCBs. Further details are described in Montenbruck O., Hauschild A., Steigenberger P., "Differential Code Bias Estimation using Multi-GNSS Observations and Global Ionosphere Maps"; ION International Technical Meeting, 26-28 Jan. 2014, San Diego (2014). Note that no QZSS DCBs are provided at present, since this constellation comprises only a single satellite and no calibrated reference station is available for separating satellite and station biases. All DCBs are provided in the Bias SINEX format http://www.biasws2012.unibe.ch/pdf/bws12_2.4.1.pdf http://www.biasws2012.unibe.ch/docs/sinex_bias_0.01-2.txt that has been proposed as a candidate exchange format for various types of inter-signal, inter-frequency- and inter-system biases. As a standard product for common user applications, GNSS satellite biases from weekly averages of daily DCBs are provided in annual files MGEX.bsx where indicates the four digit year. A full set of daily satellite AND station biases MGEX_all.bsx is provided for reference purposes and trend analyses. Note that station DCBs are not required in common positioning applications where they will typically be absorbed in clock offsets or inter-system biases. The above products are initially made available for the full year of 2013 and the first 1.5 months of 2014. Updates covering later periods are planned on a quarter-year basis. The bias products can be retrieved from the MGEX product archive at CDDIS ftp://cddis.gsfc.nasa.gov/pub/gps/products/mgex/dcb and the corresponding mirror site ftp://igs.ign.fr/pub/igs/products/mgex/dcb hosted by the IGN. Kind regards, Oliver Montenbruck (on behalf of the MGEX project and the IGS Multi-GNSS Working Group) -- Oliver Montenbruck DLR, German Space Operations Center Oberpfaffenhofen D-82234 Wessling Germany Tel. +49 (8153) 28-1195