[IGSMAIL-6868] New MGEX Multi-GNSS DCB Product

[Oliver Montenbruck]

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<yyyy>.bsx

where <yyyy> indicates the four digit year. A full set of daily
satellite AND station biases

   MGEX<yyyy>_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
Fax     +49 (8153) 28-1450
e-mail  oliver.montenbruck at dlr.de