Changes between Version 204 and Version 205 of PublicPages/MayallZbandLegacy/NotesforObservers

Timestamp:

Aug 31, 2017 12:04:16 PM (7 years ago)

Author:

Arjun Dey

Comment:

--

PublicPages/MayallZbandLegacy/NotesforObservers

@@ -327 +327 @@
 ''No on-sky observations are permitted before 10 deg twilight.'' [wiki:MayallZbandLegacy/NotesforObservers/TenDegTwilight]
 
+ 1. Check Telescope Pointing:: 
  1. At start of night, check telescope pointing (see item 8.4 above; you should already be there! For B-semester observing, use the pointing coordinate 270.0, +60.0) by doing the following: 
         (a) create an OBJECT script with NGUI for 5 sec with the zd filter  (do not create a TEST script, because MOSSTAT will ignore it)
@@ -334 +335 @@
         (c) Once the image is processed by copilot, the bottom panel on the copilot plot will print the pointing offsets. Give these offsets to the OA with '''opposite''' sign.  That is, if copilot shows numbers (-15.3,+18.3), or if mosstat reads "RA,Dec offsets = -15.34, 18.32", then you need to provide the OA with the pointing offsets of +15,-18 to zero the telescope coordinates.[[BR]][[BR]]
 
-If this process does not work for some reason, then you can also zero the telescope coordinates by using a bright star placed on the telescope boresight (defined as the center of the mosaic3 focal plane; ''i.e.'' in the chip gaps). As before, when taking the image of the bright star, make sure to create an OBJECT script with NGUI (not a TEST, because MOSSTAT will ignore it), zd filter, 1 - 5 sec exposure.  After centering the bright star, return to the first target field and use the above procedure to determine the pointing offsets - do not use the copilot or mosstat results based on the bright star image! [[BR]][[BR]]
+If this process does not work for some reason, then you can also zero the telescope coordinates by using a bright star placed on the telescope boresight (defined as the center of the mosaic3 focal plane; ''i.e.'' in the chip gaps). As before, when taking the image of the bright star, make sure to create an OBJECT script with NGUI (not a TEST, because MOSSTAT will ignore it), zd filter, 1 - 5 sec exposure.  After centering the bright star, return to the first target field and use the above procedure to determine the pointing offsets - do not use the copilot or mosstat results based on the bright star image! Make sure you move back to the first MzLS tile position after you complete this test. [[BR]][[BR]]
 
 If mosstat or copilot fails, it could be because (a) the telescope is mis-pointed, (b) the telescope is out of focus (set the focus approx using the formula above and try again). [[BR]][[BR]]
 You can take another OBJECT frame if you want to check to make sure the offset went in the right direction.
 
- 1. Move back to the first MzLS tile position from item 8.4.
- 1. Focus the telescope
-    - Create a focus script using the NGUI: exposure time 5 or 10 seconds, zd filter, -75 micron focus steps, click Midpoint to *on*, 9 exposures. 
+  2. Focus the Telescope::
+    - Create a focus script using the NGUI: exposure time 5 or 10 seconds, zd filter, -75 micron focus steps, click Midpoint to *on*, 9 exposures. NOTE: If observing in the 2017B semester, please make sure you are focusing at the sky location 270,+60. Also, we are having problems with the focus scripts. Please use step size of -125 micron and 5 steps for the first sequence, and then -75 micron and 5 steps for the second check.
     - run the focus script from the /home/observer/exec directory (./FOCUS.sh)
     - copilot will automatically analyze and report the best focus in the mayall-idl window.