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<tt>Oops, Vivek points out to me that it was actually *ea20*. ea21
was on *N01*, which is inline with the W arm and so not visible
from the webcam, and I mis-labeled my initial email to ops/wye
about the missing panel, assuming the first visible pad on the
north arm was N01 (ea20). (I was looking at the webcam photos
that morning for a timelapse of the move.) <br>
<br>
The antenna which lost the panel was on the first visible (i.e.,
unobscured by antennas on the west arm) pad on the north arm,
which I believe to be N02, and this was, indeed, ea20, *not* ea21.<br>
<br>
</tt><tt><tt>Sorry for the confusion. (Alas. That would have been
too neat an explanation!)<br>
</tt> <br>
Curiously, however, although ea20/N02 was one of the first to move
in to D-config (on Oct 24, apparently), it apparently doesn't get
a position update until Nov 17/18, more than 3 weeks after it
moved. It was stowed for a ~day (until the panel was retrieved),
but it did observe the next day (see photo in previous note), and
presumably through early November. The total position error on
Nov 17 was 2.2cm....<br>
<br>
(I wonder what the ea20's holography looks like? Was the panel
re-mounted to better than a few mm??)<br>
<br>
-George<br>
</tt><br>
<br>
<div class="moz-cite-prefix">On 7/9/20 12:21 PM, George Moellenbrock
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:e07d6edc-d56b-7fda-c6bf-0ff9f5c9a141@nrao.edu">
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<tt>Here's some pics I sent to Bryan documenting the missing
panel, and the weather that caused it.<br>
<br>
Not quite clear it is at one of the 'cardinal' points on the
edge.<br>
<br>
And it can't explain both of your bad edge panels in the
holography, of course!<br>
<br>
-George<br>
<br>
</tt>
<div class="moz-forward-container"><br>
<br>
-------- Forwarded Message --------
<table class="moz-email-headers-table" cellspacing="0"
cellpadding="0" border="0">
<tbody>
<tr>
<th valign="BASELINE" nowrap="nowrap" align="RIGHT">Subject:
</th>
<td>missing panel pics</td>
</tr>
<tr>
<th valign="BASELINE" nowrap="nowrap" align="RIGHT">Date:
</th>
<td>Thu, 31 Oct 2019 09:24:42 -0600</td>
</tr>
<tr>
<th valign="BASELINE" nowrap="nowrap" align="RIGHT">From:
</th>
<td>George Moellenbrock <a class="moz-txt-link-rfc2396E"
href="mailto:gmoellen@nrao.edu" moz-do-not-send="true"><gmoellen@nrao.edu></a></td>
</tr>
<tr>
<th valign="BASELINE" nowrap="nowrap" align="RIGHT">To: </th>
<td>Bryan Butler <a class="moz-txt-link-rfc2396E"
href="mailto:bbutler@nrao.edu" moz-do-not-send="true"><bbutler@nrao.edu></a></td>
</tr>
</tbody>
</table>
<br>
<br>
Hi Bryan-<br>
<br>
I attach some pics of the missing panel.<br>
<br>
missing_panel2.jpg is an early close-up (when I noticed the
missing panel; someone else had zoomed the camera)<br>
missing_panel3.jpg shows the panel lying near the center of the
dish to the left of the feed housing.<br>
missing_panel5.jpg shows the panel has slid to the edge of the
dish; at this point, Vivek and I called the operator to have the
antenna stowed and the panel retrieved<br>
<br>
BeforeAfter.gif toggles between UTC=150859 and 150910, which
shows when it actually happened: ~9:09am MDT. (Enlarged from web
cam photos I was capturing at a wide angle to observe the move
into D-array--alas frustrated by the wind.)<br>
<br>
WindPlot.png is the weather station wind plot which shows that
the wind reached it peak sustained level (~40mph, gusts to
50mph) at the same time. Apparently, the whole array got a
panel mount integrity test for ~2 hours, at least for the WSW
facing edges.....<br>
<br>
NextDay.jpg shows the antenna observing with the absent panel.<br>
<br>
Chris and Ephraim have photos from the site guys from inside the
dish, showing some impact damage to another panel, and a view
out through the gap.<br>
<br>
-George<br>
<br>
<br>
<br>
<br>
<br>
<br>
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