Subject: [IGSMAIL-0666] PGGA news items
From: Yehuda Bock
Date: Sat, 9 Jul 1994 9:30:59 PDT

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IGS Electronic Mail      Sat Jul  9  9:30:59 PDT 1994      Message Number 0666
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Author: Yehuda Bock
Subject: PGGA news items

Date: 9 July 1994

Please note the following PGGA news items:

(1) There was a large fire near the SIO Pinyon Flat Observatory (PFO)
on Saturday July 2 causing extensive damage. Several geophysical
instruments at the observatory were destroyed or damaged including the laser
strainmeters. The PGGA GPS equipment was not damaged but the observatory
lost power and communications which have not yet been fully restored.
PIN1 has lost about 1 week of data but we expect that it will be on
line shortly.  Please direct any detailed questions about the observatory
to Frank Wyatt or Duncan Agnew (wyatt/[email-masked].)

(2) There has been some confusion at the new PGGA site at Monument Peak
concerning the antenna height. The earlier reported height was from the
top of a fixed cylinder (attached to the monument rod) to the antenna
pre-amp base. Since this cylinder can be unscrewed from the rod we have
re-defined the monument mark to be a divot on the rod (which was the
original intention of Frank Wyatt, the designer and builder of the
monument). Thus, physically there has been no change in the antenna setup
but only the definition has changed.  The antenna height changes then
from 0.039 m to 0.080 m as recorded in an updated IGS log. This change
will go into affect in the SIO PGGA processing starting GPS week 757.
We apologize for any inconvenience to users of these data. 

(3) We are testing a new Ashtech antenna at the SIO3 site. It is lighter
and has a larger and more uniform ground plane than the previous design,
to reduce multipath effects. This change went into affect on 28 May as
recorded in an updated IGS log. We are currently conducting tests to
determine the phase center offsets for this new antenna.

(4) A new PGGA site was installed on 15 June at Crafton Hills Community College
in Yucaipa, California by UCLA and SIO. The distribution of the site form
is delayed until we receive some missing information. Data are available from
the SIO archive (site code CRFP). The site has an Ashtech Z-12 receiver with
and BPA antenna height of 0.0355m.

(5) We are in the process of upgrading all the PGGA Ashtech Z-12 receivers
to the newly released 1D00 firmware. Exact dates are recorded in the updated
IGS log. Sites MONP, SIO3, and VNDP are already upgraded. Sites CRFP, PIN1,
CRFP, and TRAK will be upgraded in a few days.

We have sent to the IGS central bureau log updates
for the following PGGA sites:

Monument Peak (MONP)
Scripps 3 (SIO3)
Vandenberg (VNDP)

[Mailed From: [email-masked] (Geodesy Lab account)]