[IGSMAIL-7173] New Multi-GNSS Differential Code Bias (DCB) Product

[Oliver Montenbruck]

Dear colleagues,

with this mail we would like to inform you about the availability
of a new DCB product of the IGS Multi-GNSS Experiment (MGEX).

The new product is generated by the Institute of Geodesy and Geophysics
(IGG) of the Chinese Academy of Sciences (CAS) in Wuhan under the lead
of Prof. Yunbin Yuan (yybgps at asch.whigg.ac.cn).

DCBs for all relevant signals of the GPS, GLONASS, BeiDou and Galileo
satellites are determined from ionosphere-corrected pseudorange
differences. Other than the current MGEX DCB product, which makes use
of CODE's global ionosphere maps for ionospheric correction, the new
CAS/IGG product employs local ionospheric model for the combined 
estimation of DCBs and ionospheric activities with the multi-GNSS 
observations.

A description of the basic algorithms used for the DCB estimation and
a comparison with other DCB products is provided in

Wang N., Yuan Y., Li Z., Montenbruck O., Tan B. (2015)
Determination of differential code biases with multi-GNSS observations,
Journal of Geodesy. DOI 10.1007/s00190-015-0867-4

which will become available online in early November.

The new DCB product is generated on a daily basis with few days of
latency. In addition to the delivery of daily products since mid
October 2015, CAS/IGG has provided past data starting from 1 Jan 2013
onwards. Similar to the previous MGEX DCB product of DLR, the new
product is provided in the prototype Bias SINEX format
(see ftp://ftp.unibe.ch/aiub/bcwg/format/draft/sinex_bias_0.01.txt ).

Both DCB products (CAS/IGG and DLR) are now made available at common
archive in the CDDIS and IGN repositories:

    ftp://cddis.gsfc.nasa.gov/pub/gps/products/mgex/dcb
    ftp://igs.ign.fr/pub/igs/products/mgex/dcb

The DCB file names

   CAS0MGXRAP_<yyyy><ddd>0000_01D_01D_DCB.BSX.gz
   DLR0MGXFIN_<yyyy>0010000_<nnu>_07D_DCB.BSX.gz
   DLR0MGXFIN_<yyyy>0010000_<nnu>_01D_DCB.BSX.gz

are based on a new naming scheme proposed for future MGEX products,
which is inherited from the new RINEX3 file naming convention and
the full specification is given as

AAAVPPPTTT_YYYYDDDHHMM_LEN_SMP_CNT.FMT[.?*]

01-03  AAA    3-char AC name (here: CAS for "Chinese Academy of
               Sciences", and DLR for "German Aerospace Center")
04       V    1-char version/solution identifier (here: nominally 0)
05-07  PPP    3-char campaign/project specification (here: "MGX")
08-10  TTT    3-char product type specification (here: RAP for "rapid",
               and FIN for "final")
11      _     1-char separator (underline)
12-15  YYYY   4-digit year of start epoch
16-18  DDD    3-digit day-of-year of start epoch
10-20  HH     2-digit hour of start epoch (her: 00)
21-22  MM     2-digit minute of start epoch (here: 00)
23      _     1-char separator (underline)
24-26  LEN    2-digits+1-char intended (nominal) product period
               (here 01D for 1-day, 01Y for 1-year and ??L for
               coverage interval in months)
27      _     1-char separator (underline)
28-30  SMP    2-digits+1-char sampling interval
               (here 01D for 1-day or 07D for 7-day averages)
31      _     1-char separator (underline)
32-34  CNT    3-char content type (here: "DCB")
35       .    1-char separator
36-38  FMT    3-char format extension (here: "BSX")

optional:
39      .     extension
40-xx         compression file type (here: ".gz")


With best regards,

Ningbo Wang (wnbigg at asch.whigg.ac.cn) and
Oliver Montenbruck (oliver.montenbruck at dlr.de)





-- 
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