[evlatests] Ku-band Holography results

[Rick Perley]

     We have started a campaign to understand why the panel settings 
implemented last year to ea20 had almost no effect on the reflector surface.

     The first step is to holographically survey a number of antennas.   
We will then deliberately move two panels by known amounts, then 
re-survey -- the goal is to determine if the holography results agree 
(both in location and displacement) with the known changes.

     The first observations were made last night -- fourteen antennas 
were surveyed -- the remaining thirteen were 'reference' antennas.   The 
spatial resolution is not high -- due to time constaints, the grid was 
limited to 30x30.  I chose Ku band for this, due its good stability and 
sensitivity.

     The results are very nice -- excellent data quality and stability.

     Key Result:

     *Nothing has Changed* since we last surveyed these antennas at 
Ku-band in Dec 2014 -- including ea20, the antenna most in need of panel 
resetting.   This result is in accordance with all other holographic 
surveys -- the surfaces don't change over time.

     I attach a number of images, showing the surface maps from Dec 2014 
(left side) and the recent results (right side) for thirteen antennas. 
    The color scale runs from -2.5 to 2.5 millimeters (grey to red).  
Red means the surface is too high, dark colors mean the surface is too 
low.   Note that the Dec 2014 data was of much higher resolution (43 x 
43 grid) than today's (30 x 30).  This explains the presence of 
small-scale features in the old images that are missing in the recent.




-------------- next part --------------
A non-text attachment was scrubbed...
Name: EA18-KU.pdf
Type: application/pdf
Size: 91865 bytes
Desc: not available
URL: <http://listmgr.nrao.edu/pipermail/evlatests/attachments/20170316/74dee3da/attachment-0013.pdf>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: EA08-KU.pdf
Type: application/pdf
Size: 78294 bytes
Desc: not available
URL: <http://listmgr.nrao.edu/pipermail/evlatests/attachments/20170316/74dee3da/attachment-0014.pdf>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: EA01-KU.pdf
Type: application/pdf
Size: 84225 bytes
Desc: not available
URL: <http://listmgr.nrao.edu/pipermail/evlatests/attachments/20170316/74dee3da/attachment-0015.pdf>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: EA22-KU.pdf
Type: application/pdf
Size: 78313 bytes
Desc: not available
URL: <http://listmgr.nrao.edu/pipermail/evlatests/attachments/20170316/74dee3da/attachment-0016.pdf>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: EA05-KU.pdf
Type: application/pdf
Size: 86009 bytes
Desc: not available
URL: <http://listmgr.nrao.edu/pipermail/evlatests/attachments/20170316/74dee3da/attachment-0017.pdf>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: EA26-KU.pdf
Type: application/pdf
Size: 81251 bytes
Desc: not available
URL: <http://listmgr.nrao.edu/pipermail/evlatests/attachments/20170316/74dee3da/attachment-0018.pdf>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: EA14-KU.pdf
Type: application/pdf
Size: 80594 bytes
Desc: not available
URL: <http://listmgr.nrao.edu/pipermail/evlatests/attachments/20170316/74dee3da/attachment-0019.pdf>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: EA04-KU.pdf
Type: application/pdf
Size: 78533 bytes
Desc: not available
URL: <http://listmgr.nrao.edu/pipermail/evlatests/attachments/20170316/74dee3da/attachment-0020.pdf>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: EA06-KU.pdf
Type: application/pdf
Size: 84330 bytes
Desc: not available
URL: <http://listmgr.nrao.edu/pipermail/evlatests/attachments/20170316/74dee3da/attachment-0021.pdf>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: EA17-KU.pdf
Type: application/pdf
Size: 80694 bytes
Desc: not available
URL: <http://listmgr.nrao.edu/pipermail/evlatests/attachments/20170316/74dee3da/attachment-0022.pdf>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: EA15-KU.pdf
Type: application/pdf
Size: 76527 bytes
Desc: not available
URL: <http://listmgr.nrao.edu/pipermail/evlatests/attachments/20170316/74dee3da/attachment-0023.pdf>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: EA25-KU.pdf
Type: application/pdf
Size: 79880 bytes
Desc: not available
URL: <http://listmgr.nrao.edu/pipermail/evlatests/attachments/20170316/74dee3da/attachment-0024.pdf>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: EA20-KU.pdf
Type: application/pdf
Size: 85570 bytes
Desc: not available
URL: <http://listmgr.nrao.edu/pipermail/evlatests/attachments/20170316/74dee3da/attachment-0025.pdf>