Goal

Requirements

• Must have control of the DEIMOS rotator
• Can be done in the afternoon; no sky time required

Procedure

1. Prepare instrument
   • Bring up DEIMOS dashboard
   • Click on TV Guider button to bring up guider control widget
   • Ensure that TV power is on
   • Insert the B guider filter
   • Turn on the Zn lamp
   • Unlock rotator
2. Start guider
   • Bring up an xterm window on k2server as k2obs
   • set DISPLAY as required
   • type dcsgui to launch the DCS GUI
   • click on the Qwik button to get menu
   • release on the desired guider version to launch guider; eventually the display window, Xguider control, and log window will appear
   • select DEIMOS guider
   • click on Image Update to enable guider readouts
   • click on Show centroid to begin printing data values for images
   • click on Binning and select 1 for unbinned mode
   • set exposure time to 2000 ms
3. Start data acquisition
   • Bring up an xterm window on deimosserver as dmoseng
   • cd to the scripts directory
   • type ./T953 to launch the T953 script
   • enter "99" as the number of images to save in Xguide, and click the nearby S button to start saving images every readout
   • monitor the datataking and click Xguide to restart datataking after 99 images have been acquired
   • Turn off the Zn lamp.

Measurement

1. Change to directory ~dmoseng/data/T953
2. Create a new subdirectory for today:

   	mkdir 2009jan26

3. Go to the new subdirectory:

   	cp 2009jan26

4. Copy logfile from summit:

       cp ~dmoseng/summit/scripts/T953.log .

5. Start idl and display first image:

   	atv, '/s/nightly2/09/01/26/cam0010.fits'

6. In ATV, measure coordinates of the central "+" on the first image.
7. Edit file ~dmoseng/idl/dmoseng/T953_measure.pro and change the initial coordinates of the central "+" on the first image:

   	xc = 513.00                     ; starting x coord
   	yc = 641.00                     ; starting y coord

8. Edit file ~dmoseng/data/T953/header.txt and add appropriate commentary at the bottom.
9. Run IDL and cd ~dmoseng/data/T953/YYYYmmmDD
10. Type .run T953_measure.pro to generate the file T953_measure.dat.
11. Type .run T953_plot.pro to generate the output files.
12. Exit IDL.
13. Type gmake to create a file all.ps which is printable for inclusion in notebook.
14. Compare results to previous runs to get a sense of change in flexure.
15. Supply new lookup table (deimos_flex.lut) to guider software guru.

Output Files

deimos_flex.lut

Flexure correction table to be used by guider software.

T953_x.ps

Plot of flexure in x direction against ROTPPOSN.

T953_y.ps

Plot of flexure in y direction against ROTPPOSN.

T953_xy.ps

Plot of flexure in x direction against flexure in y direction.

Preliminary Conclusion

• Flexure measured on 2002-Jun-12 had peak-to-peak amplitude of 7 px in x and 5 px in y, with generally sinusoidal variation.
• Flexure measured on 2002-Jul-03 had peak-to-peak amplitude of 2.3 px in x and 5.1 px in y, with generally sinusoidal variation.
• Flexure measured on 2002-Sep-26 had peak-to-peak amplitude of 1.3 px in x and 4.3 px in y. The shape of the overall (x,y) curve is nearly linear.
• Flexure measured on 2008-Jun-11 had peak-to-peak amplitude of 2.1 px in x and 3.6 px in y. The shape is sinusoidal in each axis, yielding an overall ellipse.
• Flexure measured on 2008-Jan-26 had peak-to-peak amplitude of 2.2 px in x and 3.6 px in y, 4.2 px overall. The shape is sinusoidal in each axis, yielding an overall ellipse.