[IGSMAIL-6161]: Update: igs05_1585.atx - update including first Block IIF satellite

[Robert Khachikyan]

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IGS Electronic Mail      28 May 12:05:41 PDT 2010      Message Number 6161
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Author: Ralf Schmid and Robert Khachikyan

Dear IGS colleagues!

The absolute IGS antenna correction file (igs05_wwww.atx) has been
updated. The new release is called 'igs05_1585.atx'. It contains the
following changes:

1) The first Block IIF satellite launched on 28 May 2010 has been added:

G25 (G062)

The following PRELIMINARY phase center offset (PCO) values were assigned:
PCO_X =  39.4 cm
PCO_Y =   0.0 cm
PCO_Z = 109.3 cm
The x- and y-components are supposed to be the nominal PCO values,
whereas the z-component is supposed to be the "official" individual
z-offset calibration provided by the manufacturer. The IGS will try to
come up with a PCO estimate consistent with igs05.atx, before SVN62 will
be set healthy. Therefore, all station operators are asked to set their
receivers to track also unhealthy satellites.

As nothing is known about the phase center variations (PCV) of the
transmitting antennas on board Block IIF, igs05.atx contains zero values
for the time being. Besides, no recommendation is made on how to correct
L5 observations so far.

Several sources:

Spaceflight Now: First-of-its-kind satellite for GPS launched into space
http://spaceflightnow.com/delta/d349/

Live coverage of the Delta 4 rocket launching the GPS 2F-1 navigation
satellite:
"GPS 2F SV-1 is scheduled to be set healthy approximately 90-120 days
after launch."
http://www.spaceflightnow.com/delta/d349/status.html

NANU Message 2010098:

> >  2.  GPS SATELLITE SVN 62 (PRN 25) WAS LAUNCHED ON JDAY 148
> >       THIS SATELLITE WILL UNDERGO EXTENSIVE ON-ORBIT CHECK OUT AND TESTING PRIOR
> >       TO BEING SET HEALTHY. FORCE DEVELOPMENT EVALUATION WILL OCCUR PRIOR TO AND
> >       AFTER THE SPACE VEHICLE IS SET HEALTHY.
> >       A USABINIT NANU WILL BE SENT WHEN THE SATELITTE IS SET ACTIVE TO
> >       SERVICE.
>    
http://celestrak.com/GPS/NANU/2010/nanu.2010098.txt


2) A 'decommission' date for the following satellite was added:

G25 (G035): 27 May 2010


The updated antenna correction model is available at
ftp://igs.org/pub/station/general/igs05_1585.atx
or
ftp://igs.org/pub/station/general/igs05.atx

Information on the upcoming switch from igs05.atx to igs08.atx may be
found at
http://www.iapg.bv.tum.de/mediadb/219045/219046/Vortrag_EGU10_schmid_final.pdf
and/or
http://www.iapg.bv.tum.de/mediadb/117723/117724/Vortrag_AGU09_schmid.pdf


With best regards,
Ralf Schmid and Robert Khachikyan
on behalf of the IGS Antenna Working Group