[IGSSTATION-2437]: Regarding changes at stations

[Jim.Ray]

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IGS Station Mail          21 Aug 07:13:20 PDT 2008      Message Number 2437
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Author: Jim Ray

Dear Station Operators,

Analysts are seeing a steady increase in unannounced or
poorly announced changes in station configurations.  This
can cause serious problems in the data analysis and waste
time for the analysts.  It is important for us to have
accurate metadata for all stations, but it absolutely
critical for the IGS05 Reference Frame (RF) stations
because their positions are held fixed to generate the
Ultra-rapid and the Rapid products.  Even though all station
positions are freely adjusted in the Final products, the RF
stations are still used to align each weekly frame.

Nearly every week it seems that some stations must be
manually rejected from the frame combination or from AC
solutions due to incomplete or late reporting of station
changes.  Data users outside the IGS ACs may be badly
affected and not even know.

For those who do not know, the IGS05 RF stations are
shown at:

http://www.igs.org/network/refframe.html

Please, for all RF stations (at least), it should be
MANDATORY to report all information that could affect a
station's position in an IGS Station Mail message BEFORE
the changes are made.  A standardized format would be
helpful, such as (at least):


Subject: changes planned at RF station XXXX

Date of planned change: CCYY-MM-DD hh:mm UTC

Receiver: current receiver
New receiver: (if changed)

Antenna: current antenna
New antenna: (if changed)

Antenna height offset: current value
New offset: (if changed)

Radome: current radome model or NONE
New radome: (if changed)


An updated site log should be filed as soon as possible
(but never more than 24 hours after any changes).  It is
NOT SUFFICIENT to simply note that some unspecified
changes will or have been made.

Your cooperation is critical and greatly appreciated.
Best regards,
--Jim