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Klaus Honscheid, 09/02/2014 07:40 PM


Observing Plan for the September 8-9, 2014 Engineering Nights

(Late) Afternoon

(possibly a super cal meaning 5 sets of zeros and flats)

Run the calibration script five times to get set of zeros and dome flats:

Script: prenight_calibration.json (note that this is a (standard) DES script. From the the Observer Console GUI select Exposure Control --> Load Exposure Script --> Select DECam Script then choose DES/prenight_calibration.json in the dialog window)

Night

Operations Tests

  • tbd (probably none)

Star Flats (Gary will update)

We have not done a valid u-band star flat since 9/2013 so this would be good to repeat. We should also take g-band star flats, since the last batch were in very poor seeing, and also it is useful to have the u-g colors to use in deriving a color term for the star flat.

Ideally we would do this in darker conditions but unfortunately this will be tough to arrange. When the moon is down near the ends of the nights, there are no low-Galactic-latitude fields available where we have good stellar density. So some compromises will be necessary. And in the early parts of the night, the full Moon is close to our favorite star-flat fields. Unfortunately it seems like star flats at the start of a night is the best option even though the Moon will be bright.

Here are three options for fields to use this month:

RA=13:27:00  DEC=-48:45:00 (at airmass <1.5 until 01:00 UT)
RA=15:00:00  DEC=-45:00:00 (at airmass <1.5 until 02:30 UT)

There are 22 exposures in the sequence, so 2 x 22 x (30+30)s = 44 minutes to do this whole thing.

The pointing is not critical (1 arcmin accuracy is fine), but you will need to move the telescope back
to the starting position when beginning each filter.

The star flats should be done in clear weather, although seeing as poor as 1.5-2" will give data of at least some value. Better seeing is better...

The 5 scripts can be found in the Engineering/engineering_20140806 folder. They are named Starflat<filter>.json_
You must move the telescope by hand to the desired starting point before running the script. Then it does everything with relative positioning.

Mamacs and Primary LUT (Aaron and CTIO to update)

From Aaron's email:

4Map Stability Test - (~30 images, 1-1.5 hours)

1) 5 images, 30 seconds, r band, close to Zenith, AOS on  (to establish alignment)

2) move to +1500 defocus by adding 1500 to  the trim_z, leave other trim at the prior values from AOS, turn AOS off, keep telescope LUT on

2a) take 2 images, 30 sec, r band with nominal 4Map setting

2b) 2 images, 30 sec, r band, 4Map ct2Mag = 100 ct2Ang = 0

2c) 2 images, 30 sec, r band, 4Map ct2Mag = 250 ct2Ang = 0

2d) 2 images, 30 sec, r band, 4Map ct2Mag = 500 ct2Ang = 0

2e) 2 images, 30 sec, r band, 4Map ct2Mag = 250 ct2Ang = 0

2f) 2 images, 30 sec, r band, 4Map ct2Mag = 100 ct2Ang = 0

2g) 2 images, 30 sec, r band, 4Map ct2Mag = 0 ct2Ang = 0

2h) 2 images, 30 sec, r band, 4Map ct2Mag = 100 ct2Ang = 180

2i) 2 images, 30 sec, r band, 4Map ct2Mag = 250 ct2Ang = 180

2j) 2 images, 30 sec, r band, 4Map ct2Mag = 500 ct2Ang = 180

2k) 2 images, 30 sec, r band, 4Map ct2Mag = 250 ct2Ang = 180

2l) 2 images, 30 sec, r band, 4Map ct2Mag = 100 ct2Ang = 180

2m) 2 images, 30 sec, r band, 4Map ct2Mag = 0 ct2Ang = 0

Alt-Az Scan (~130 images plus slews - about 4 hours)

3) move back to in-focus, move back to Zenith, restore the nominal 4Map setting, 5 images, 30 seconds, r band, close to Zenith, AOS on  (to re-establish alignment)

4) move to +1500 defocus with the trim_z, leave other trim at values from AOS, turn AOS off, keep telescope LUT on

4a) 2 images, 30 sec, r band, Zenith

4b-4z) 2 images, 30 sec each, r band at elevations of 82.5, 75, 60, 45, 30 with 30 deg spacing in Azimuth — ie. the desired LUT elevation & azimuth points

*Notes:*

In July Roberto replied that he’d prefer to do this test without the 360 nm baseline Astigmatism correction, if I understood correctly.  That is perfectly fine with me.