[IGSMAIL-5668]: GLONASS negative frequency channels

[Stefan Schaer]

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IGS Electronic Mail      30 Nov 06:28:46 PST 2007      Message Number 5668
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Author: Stefan Schaer


Dear IGS/IGLOS colleagues and station operators,

The IGS/IGLOS GNSS receiver network is not yet completely ready for
GLONASS negative frequency channels.

We already have 2 GLONASS satellites transmitting on zero or negative
frequency channels: R15 on channel 0 and R17 on channel -1. With the
satellites of the upcoming December 2007 triple launch (presumably all
will be assigned to negative frequency channels), we may soon have 5
GLONASS satellites transmitting on zero or negative frequency channels.

Tracking situation concerning (operational) R15:

http://www.aiub.unibe.ch/download/igsdata/y2007/odata_glonass_d283.txt
http://www.aiub.unibe.ch/download/igsdata/y2007/odata_glonass_d284.txt
http://www.aiub.unibe.ch/download/igsdata/y2007/odata_glonass_d285.txt
http://www.aiub.unibe.ch/download/igsdata/y2007/odata_glonass_d286.txt

Tracking situation concerning (operational) R15 and (unusable) R17:

http://www.aiub.unibe.ch/download/igsdata/y2007/odata_glonass_d332.txt
http://www.aiub.unibe.ch/download/igsdata/y2007/odata_glonass_d333.txt
http://www.aiub.unibe.ch/download/igsdata/y2007/odata_glonass_d334.txt
http://www.aiub.unibe.ch/download/igsdata/y2007/odata_glonass_d335.txt

See also:

http://www.aiub.unibe.ch/download/igsdata/odata_glonass_day.txt

On 24 Oct 2007, just 17 of 66 GPS/GLONASS tracking stations were able
to track GLONASS negative frequency channels. See IGS Mail 5650:

http://igscb.jpl.nasa.gov/mail/igsmail/2007/msg00130.html

Meanwhile, 45 of 74 IGS/IGLOS stations are ready for GLONASS negative
channels. That seems to be the case by default for Leica, Novatel,
Trimble GNSS receivers. Javad and Topcon GNSS receivers are unable to
track negative channels until latest firmware is installed (2.6.0 and
3.2, respectively). Please note that we post an automatically created
list with respect to the current R15 and R17 IGS/IGLOS receiver
tracking status to:

http://www.aiub.unibe.ch/download/igsdata/tracking_r15.txt
http://www.aiub.unibe.ch/download/igsdata/tracking_r17.txt

Station operators responsible for stations that are indicated with "FW
to be upgraded" are kindly asked to upgrade the receiver firmware to
the latest version in order to enable tracking of the complete GLONASS
constellation. Action must be taken with regard to the following (21)
stations:

bogi  JPS E_GGD           2.4 SEP,02,2004
bogo  TPS EUROCARD        2.3 MAY,13,2003 P1
cagz  TPS E_GGD           2.6 MAR,16,2006
como  TPS E_GGD           3.1 JAN,24,2007 P1
crar  TPS ODYSSEY_E       2.5 JUN,22,2005 P1
darr  TPS LEGACY          2.3P4
hueg  JPS LEGACY          EURO_3 / 2.3P4
metz  JPS EUROCARD        2.3 NOV,12,2002
mobj  TPS LEGACY          2.3 APR,28,2004 P4
mtbg  TPS GB-1000
onsa  JPS E_GGD           2.3 FEB,17,2004 P4B2
park  JPS E_GGD           V2.5
pous  TPS GB-1000         2.5 APR,07,2005 P1B1
snec  TPS GB-1000         2.5 JUN,22,2005 P1
spt0  JPS LEGACY          2.3 APR,28,2004 P4
str2  TPS E_GGD           2.5P1
sunm  JPS LEGACY          JPS_4 / 2.3 NOV,12,
thu2  JPS LEGACY          2.3 APR,28,2004 P4
tixj  TPS ODYSSEY_E       2.5 JUN,22,2005 P1
unpg  TPS ODYSSEY_E       2.5 FEB,21,2005
wtzr  TPS NETG3           3.1 JUN,28,2007 P3

It is worth mentioning that there is a number of upgraded Javad
receivers that shows improved performance after the firmware upgrade.
Examples are:

http://igscb.jpl.nasa.gov/network/site/dlft.html
http://igscb.jpl.nasa.gov/network/site/irkj.html
http://igscb.jpl.nasa.gov/network/site/khaj.html
http://igscb.jpl.nasa.gov/network/site/mdvj.html
http://igscb.jpl.nasa.gov/network/site/sofi.html
http://igscb.jpl.nasa.gov/network/site/unbj.html
http://igscb.jpl.nasa.gov/network/site/wtzj.html

ohi2 is an exception (concerning multipath):

http://igscb.jpl.nasa.gov/network/site/ohi2.html

Ashtech Z18 receivers cannot be upgraded for tracking of GLONASS
negative frequency channels. From our point of view, a replacement of
the old-aged Z18 receiver model becomes more and more desirable:

godz  ASHTECH Z18         0065      ZT16
gope  ASHTECH Z18         0065
hert  ASHTECH Z18         0065      ZT16
joz2  ASHTECH Z18         0064
mat1  ASHTECH Z18         0065      ZT16
mtka  ASHTECH Z18         0065      ZT16
reun  ASHTECH Z18         0065
unfe  ASHTECH Z18         0065      ZT17

Many thanks to all IGS/IGLOS Javad or Topcon station operators who
already made a corresponding firmware upgrade at their receivers.

Best regards,

The CODE AC Team