[IGSMAIL-6662] igs08_1707.atx: Update including JPSREGANT subtype calibrations & R743
Ralf Schmid
schmid at dgfi.badw.de
Mon Sep 24 09:00:36 PDT 2012
Dear IGS colleagues!
The absolute IGS antenna correction file (igs08_wwww.atx) has been
updated. The new release is called 'igs08_1707.atx'. It contains the
following changes:
1) Subtype calibrations provided by Geo++ GmbH for two Javad antennas
(JPSREGANT_DD_E, JPSREGANT_SD_E):
JPSREGANT_DD_E1 NONE
JPSREGANT_DD_E2 NONE
JPSREGANT_SD_E1 NONE
JPSREGANT_SD_E2 NONE
Those calibrations will be needed for the switch from the reference
frame realization IGS08 to IGb08 that should take place on 7 October
2012, the start of GPS week 1709 (to be announced in a further IGSMail).
As the switch to the subtype calibrations will cause coordinate changes
for all affected stations, the subtype antenna names should not be
considered before IGb08 is adopted. More details can be found below.
2) The last out of three GLONASS-M satellites launched on 4 November
2011 was added with a preliminary z-offset value of 245 cm:
R743 (R08)
Compare [IGSMAIL-6660], [IGSMAIL-6661] as well as the following message
provided by the Information-Analytical Centre:
> According to GLONASS System Control Centre, the Glonass-M #743 SV residing near orbital slot 2 will be set healthy on 20 September 2012 at 18:30 (MT). In the almanac Glonass-M #743 will be designated under system number 8
http://www.glonass-ianc.rsa.ru/en/content/news/?ELEMENT_ID=324
3) One additional robot calibration provided by Geo++ GmbH:
ASH701023.A NONE
This single-frequency antenna type was installed at the M-GEX station
GRAC (Grasse) between 1998 and 2000:
http://igs.org/igscb/station/pendinglogs/grac/grac_20111019.log
4) One robot calibration provided by Leica Geosystems AG and performed
by Geo++ GmbH:
LEIGS08PLUS NONE
The updated antenna correction model is available at
ftp://igs.org/pub/station/general/igs08_1707.atx
or
ftp://igs.org/pub/station/general/igs08.atx
With best regards,
Ralf Schmid and Robert Khachikyan
on behalf of the IGS Antenna Working Group
Why subtype calibrations for the JPSREGANT antennas?
----------------------------------------------------
Sometime in 2000, Javad changed the setup of two of its JPSREGANT
antenna types (JPSREGANT_DD_E, JPSREGANT_SD_E) that introduced a 3-4 cm
position bias (mainly in the vertical component). Unfortunately, these
new subtypes did not produce a new name definition and proper
recognition within the IGS. At first, this was only a problem for those
IGS stations that were equipped with the new subtypes.
With the switch from igs_01.pcv to igs05.atx in November 2006, mean PCV
values over the two subtypes were adopted for both antenna types. Since
that time, all stations equipped with one of the JPSREGANT antenna types
are affected by a vertical bias of up to 2 cm that shows up in
coordinate time series, if the antenna is exchanged. Extremely
disadvantageous are such biases furthermore, if so-called local ties
with respect to nearby located instruments are considered.
As the IGS aims at estimating station coordinates with an accuracy of a
few mm, coordinate biases of 2 cm cannot be ignored. However, as not
only the antenna types, but also the station coordinates have to be
corrected, the problem can only be solved in conjunction with an update
of the IGS reference frame. As the switch from IGS05 to IGS08 was
missed, the transition to IGb08 represents another opportunity.
Which stations are affected?
----------------------------
According to Geo++, the subtypes are defined as follows (as Geo++ didn't
get each single antenna for calibration, the classification can only be
vague; especially with respect to JPSREGANT_SD_E, the exact borderline
is unknown):
> | JPSREGANT_DD_E1 | Dual -depth chokering antenna, external |
> | | different PCV due to systematics within series; |
> | | no unique criteria, but guess is serial number RA |
> | JPSREGANT_DD_E2 | Dual -depth chokering antenna, external |
> | | different PCV due to systematics within series; |
> | | no unique criteria, but guess is serial number RRA |
> | JPSREGANT_SD_E1 | Single-depth chokering antenna, external |
> | | different PCV due to systematics within series; |
> | | no unique criteria, but guess is serial number |
> | | below RA0131 |
> | JPSREGANT_SD_E2 | Single-depth chokering antenna, external |
> | | different PCV due to systematics within series; |
> | | no unique criteria, but guess is serial number |
> | | above RA0132 |
ftp://igs.org/igscb/station/general/rcvr_ant.tab
With the help of the classification given above, the Antenna Working
Group tried to identify all subtypes ever installed within the IGS
network. If possible, the subtype was also verified by the
purchase/installation date, by the analysis of coordinate time series as
well as of coordinate or troposphere ties. With one exception (IRKJ),
the additional evidence was always consistent with the subtype assumed
from the serial number of the antenna alone.
Active IGS stations:
| Site | Antenna subtype | Installed | Removed | S/N |
|------|----------------------|------------|------------|--------|
| CAGZ | JPSREGANT_DD_E2 NONE | 2001-10-01 | !!ACTIVE!! | RRA052 |
| CONZ | JPSREGANT_DD_E1 NONE | 2002-05-16 | 2005-05-17 | RA0178 |
| DLFT | JPSREGANT_SD_E1 NONE | 1999-02-17 | 1999-03-29 | RA0043 |
| DLFT | JPSREGANT_DD_E1 NONE | 1999-03-29 | 2004-03-08 | RA0077 |
| DLFT | JPSREGANT_DD_E1 NONE | 2004-03-08 | dormant? | RA0077 |
| FFMJ | JPSREGANT_SD_E2 NONE | 2002-02-18 | 2005-05-19 | RA0294 |
| HUEG | JPSREGANT_SD_E2 NONE | 2002-02-21 | 2005-12-05 | RA0310 |
| HUEG | JPSREGANT_SD_E2 NONE | 2005-12-05 | 2008-03-13 | RA0291 |
| KHAJ | JPSREGANT_SD_E1 NONE | 2001-07-18 | dormant? | RA0032 |
| MDVJ | JPSREGANT_DD_E1 NONE | 2001-07-18 | !!ACTIVE!! | RA0195 |
| MOBJ | JPSREGANT_SD_E1 NONE | 2007-05-24 | !!ACTIVE!! | RA0033 |
| MOBK | JPSREGANT_SD_E1 NONE | 2007-05-24 | !!ACTIVE!! | RA0033 |
| MTBG | JPSREGANT_DD_E1 NONE | 1999-07-01 | 2008-11-09 | RA0085 |
| NOVM | JPSREGANT_SD_E1 NONE | 2006-11-07 | !!ACTIVE!! | RA0038 |
| STR2 | JPSREGANT_DD_E1 NONE | 2000-02-18 | 2003-01-18 | ???005 |
| TITZ | JPSREGANT_SD_E2 NONE | 2001-09-27 | 2003-01-14 | RA0291 |
| TITZ | JPSREGANT_SD_E2 NONE | 2003-01-14 | 2008-02-20 | RA0311 |
| UNBJ | JPSREGANT_DD_E1 NONE | 2001-05-23 | 2012-06-01 | RA0193 |
| ZIMJ | JPSREGANT_SD_E1 NONE | 1999-02-03 | dormant | RA0059 |
|------|----------------------|------------|------------|--------|
Former IGS stations:
| Site | Antenna subtype | Installed | Removed | S/N |
|------|----------------------|------------|------------|--------|
| DREJ | JPSREGANT_SD_E2 NONE | 2001-09-05 | 2002-02-01 | RA0290 |
| DREJ | JPSREGANT_SD_E2 NONE | 2002-04-04 | 2003-11-17 | RA0292 |
| DREJ | JPSREGANT_SD_E2 NONE | 2003-11-17 | 2007-03-06 | RA0293 |
| DWH1 | JPSREGANT_DD_E1 NONE | 2000-10-05 | ????-??-?? | RA0083 |
| KOU1 | JPSREGANT_DD_E2 NONE | 2002-01-20 | ????-??-?? | RRA31 |
| NOVJ | JPSREGANT_SD_E1 NONE | 2001-07-24 | ????-??-?? | RA0038 |
| SUNM | JPSREGANT_SD_E1 NONE | 2001-06-12 | 2010-10-12 | RA0024 |
| UNB1 | JPSREGANT_DD_E1 NONE | 2001-05-23 | ????-??-?? | RA0193 |
| WTZJ | JPSREGANT_SD_E2 NONE | 2002-04-11 | 2005-08-02 | RA0295 |
|------|----------------------|------------|------------|--------|
Not corrected: IRKJ (JPSREGANT_SD_E NONE)
In this special case, only a verification of the serial number or an
individual calibration of the antenna after the decommissioning will
bring clarity.
Expected station position changes
---------------------------------
For the affected IGS08/IGb08 stations, differential PPP tests were
carried out individually to estimate the impact of the phase center
calibration change on the position. The position changes of
non-IGS08/IGb08 stations are based on latitude-dependent models (compare
[IGSMAIL-6356]) that are available upon request. The estimated station
position changes [mm] are (provided by Paul Rebischung without any
warranty):
| Site | Antenna subtype | dE dN dH | IGb08 |
|------|----------------------|-------------------|-------|
| CAGZ | JPSREGANT_DD_E2 NONE | +0.4 +0.1 +9.5 | X |
| CONZ | JPSREGANT_DD_E1 NONE | -1.3 -1.7 -22.0 | X |
| DLFT | JPSREGANT_SD_E1 NONE | -0.7 +0.2 -16.2 | - |
| DLFT | JPSREGANT_DD_E1 NONE | -0.9 -2.2 -17.9 | - |
| DREJ | JPSREGANT_SD_E2 NONE | +0.5 -0.1 +14.8 | - |
| DWH1 | JPSREGANT_DD_E1 NONE | -0.9 -2.0 -18.3 | - |
| FFMJ | JPSREGANT_SD_E2 NONE | +0.5 -0.1 +14.9 | - |
| HUEG | JPSREGANT_SD_E2 NONE | +0.4 -0.2 +15.1 | - |
| KHAJ | JPSREGANT_SD_E1 NONE | -0.6 +0.4 -17.6 | X |
| KOU1 | JPSREGANT_DD_E2 NONE | +0.4 -0.2 +10.2 | - |
| MDVJ | JPSREGANT_DD_E1 NONE | -0.6 -2.3 -19.3 | X |
| MOBJ | JPSREGANT_SD_E1 NONE | -0.7 +0.2 -15.7 | - |
| MOBK | JPSREGANT_SD_E1 NONE | -0.7 +0.2 -15.7 | - |
| MTBG | JPSREGANT_DD_E1 NONE | -0.9 -2.0 -18.3 | - |
| NOVJ | JPSREGANT_SD_E1 NONE | -0.7 +0.2 -15.7 | - |
| NOVM | JPSREGANT_SD_E1 NONE | -0.7 +0.2 -15.7 | - |
| STR2 | JPSREGANT_DD_E1 NONE | -1.4 -1.8 -20.6 | - |
| SUNM | JPSREGANT_SD_E1 NONE | -0.3 +0.2 -15.2 | - |
| TITZ | JPSREGANT_SD_E2 NONE | +0.5 -0.1 +14.8 | - |
| UNB1 | JPSREGANT_DD_E1 NONE | -0.9 -2.0 -18.5 | - |
| UNBJ | JPSREGANT_DD_E1 NONE | -0.9 -2.0 -18.5 | - |
| WTZJ | JPSREGANT_SD_E2 NONE | +0.5 -0.2 +15.0 | - |
| ZIMJ | JPSREGANT_SD_E1 NONE | -0.6 +0.5 -17.4 | X |
|------|----------------------|-------------------|-------|
Steps to consider the antenna subtypes
--------------------------------------
With "igs08_1707.atx", the necessary subtype calibrations are made
available. However, they should not be used before IGb08 is adopted. At
the same day when IGb08 is adopted (probably 7 October 2012), the IGS
will provide updated site logs including the subtype antenna names for
all stations given above. The files "igs.snx" as well as
"igs_with_former.snx" are derived automatically from those site logs and
will, thus, contain the correct subtype antenna names shortly
thereafter. The file "IGb08.snx" that will be made available together
with the announcement of IGb08 will already contain the correct
JPSREGANT subtypes.
With a view to the second IGS reprocessing campaign repro2, also the
subtypes of decommissioned and former antennas will be corrected.
However, for the general IGS user mainly those stations are interesting,
where JPSREGANT antennas are still active. If dormant stations (DLFT,
KHAJ, ZIMJ) are ignored, special attention should be paid to the
following five stations:
CAGZ
MDVJ
MOBJ
MOBK
NOVM
Station operators of those five stations are urged to consider the
correct subtype name in their RINEX headers starting with the adoption
of IGb08. In preparation for repro2, it is the intention that also the
headers of historical RINEX files should be corrected.
Users are asked to update their station metadata files in time, if
necessary. Those users who want to transform old results to be
consistent with the new frame are referred to [IGSMAIL-6356].
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