ENR CTIO Blanco 4-m 2016-01-26

Date:

Tuesday, January 26, 2016

Telescope:

CTIO Blanco 4-m

Submitter:

David James

Submitter Email:

djj@ctio.noao.edu

Observer Support:

Manuel Hernandez

Night Assistant:

Claudio Aguilera

Also Present:

Katelyn Allers, Everett Schlawin, Nicole David

Problems:

Engineering for ARCoIRIS: Detailed comments below.

Comments:

Fourth and last night of our final Commissining/engineering run for the ARCoIRIS instrument.

This afternoon, Nicole David (assisted by Manuel Hernandez) conducted optical engineering tests in

the Cassegrain cage, testing different filters with the internal calibration unit. For four different

filters, we tested the colour balance of the Qz flat-fields as measured by ARCoIRIS. Results are as

follows [Spectral orders are 8-->3, left-to-right on the colour-balance plots].

Filter BG3: too little flux in spectral orders 4 & 5, although the bluest order (#8) now has enough

flux. This filter should not be used.

[see https://www.dropbox.com/s/geiuo2nvhfwv6mc/ColourBalance-Qz-BG3.jpg?dl=0]

Filter KC5: This filter seems to act as a neutral density filter in the sense that *very*, very little

flux was measured across the entire ARCoIRIS wavelength range. DO NOT USE.

[see https://www.dropbox.com/s/7cvff68604k1dk6/ColourBalance-Qz-KC5.jpg?dl=0]

Filter RG780: This filter did not seem to change the colour-balance of the Qz flat-field by very much

at all, and order #8 still contains very little flux.

[see https://www.dropbox.com/s/c5eltujeqolilli/ColourBalance-Qz-RG780.jpg?dl=0]

Filter KG1: The colour balance of this filter is very bad, with essentially no flux in spectral orders

5-8. These data are considerably worse than having no filter at all.

[see https://www.dropbox.com/s/m998nhmo55itir7/ColourBalance-Qz-KG1.jpg?dl=0]

In conclusion, none of these filters really had the desired effect of normalizing the colour balance

of the ARCoIRIS flat-fields with the Qz lamp. The domeflats that we are acquiring with the COSMOS

top-ring lamps are pretty good actually, where we can successfully trace the spectral orders and

flat-field the ARCoIRIS data. We would prefer a better system, but at the present time we can

successfully operate with the COSMOS lamp-system until an improved colour-balance solution for the

internal calibration unit can be found.

Omar E. and Rolo C. have today held discussions, distributed by email, regarding the Blanco TCS

definition of rotator angle, and its relationship with both the parallactic angle and the instrument

mechanical angle. They are implementing changes to the TCS to allow clearer definition of the

parallactic angle, allowing the telescope operators to directly enter parallactic angle as a rotator

angle driver.

Marco continues to work on his vacations, and today has greatly improved the ARCoIRIS control

environment, including security/safe mode features: His improvements, and their testing, include:

(a) "test" button on the Spectrograph Detector GUI, allowing the user to take a test spectrum, which

is displayed, and saved/over-written to /tmp/test.fits. We ran tests of this feature, and it works

well -- thanks MB!

(b) We tested the OBSTYPE=calibration function tonight, with some successes while some irregularities

remaining. For all comparison lamps, except for the Xenon lamp test, once the TOs power-on the lamps

through the TCS GUI, we find the following.

b-I): taking a single spectrum results in an arc lamp spectrum as expected, but the lamp stays on.

b-II): taking another single spectrum, the software turns the arc lamp off, and proceeds to take

an image (essentially a dark frame).

This is good -- however, we probably want to turn off the arc lamp immediately after the first

spectrum to allow enough time for the lamp to completely turn off and dim completely before taking

the lamps-off image.

We note that when we tested the Xenon lamp, the software changed behaviour. When we took a single

spectrum, by pressing "start" as normal, a first image was taken (which is a nice arc lamp spectrum),

followed by the lamp being turned off, and a second image being taken (a dark frame). So, a single

press of the "start" button resulted in two images ... an arc and a dark ... which is actually what

we want to have happen. **After** your vacation Marco, can you please investigate these different

behaviours ?

(9-o'clock) for the 270-degree rotator angle. For rotator angles of 0-degrees, 90-degrees (or

very nearly, because the rotator cannot actually reach exactly 90-degrees) and 180-degrees, the

compass points to the wrong place. Marco, I'll make a schematic for you, showing how the compass

actually points as a function of rotation angle.

(d) Marco notes that he is quite-rightly deferring testing of various issues and requested control

environment upgrades detailed in last night's E-o-N report until the instrument is off-telescope

and back in the Coude room.

We note that the GS3 GMAP GUI on the pcguider machine has a couple of oddities.

(d-I) The UT time is 17-minutes behind that of the TCS reported UT time (which agrees with that

of the US Naval Observatory).

(d-II) The calculation of its Parallactic Angle is 10s of degrees different from the Parallactic

Angle that the ARCoIRIS TCS panel shows (which agrees with that of the JSkyCalc tool).

We note that one (only one) image from the previous night's data (25-Jan-2016), image SPEC_Eng0400,

contained null or blank TCS information across all FITS header fields. Did the TCS handshake fail,

or was this a different error internal to the TCS ?

We thoroughly tested the GUI_Tool_GRID feature "to to BB", which allows the user to slew from an

on-slit nod position to a Background Box, placed at some off-slit location on the SlitViewer

detector. This feature allows the user to acquire a sky-background spectrum for an extended source

for instance. Marco, this new feature works extremely well, with only one small error/failure.

For a simple one position nodding pattern, A --> BackBox, the observations worked well. The same

is true for two, three and four nodding positions; That is to say,

Nod A --> BackBox (return to A)

Nod A --> BackBox, Nod B --> BackBox (return to A)

Nod A --> BackBox, Nod B --> BackBox, Nod C --> BackBox (return to A)

Nod A --> BackBox, Nod B --> BackBox, Nod C --> BackBox, Nod D --> BackBox (return to A)

These tests were all successful.

However, when we used these four nod positions, and included a "repeats" entry of 3, the

observations all executed as expected, but on the very final step, the final BackBox exposure

was observed, but the star was *not* returned to position A. This was the only error/failure.

All observations were still executed, but the procedure did not quite finish.

Finally, using a rich star field (open cluster NGC 2527), we confirm the orientation of the SV

field as a function of rotator angle (see https://www.dropbox.com/s/kf85hkor8uv0c83/ARCoIRIS-onsky-OrientationJan2...).

All-in-all, a busy and thoroughly successful night !

saludos

DJJ, KNA, ES, ND

Conditions:

General Conditions

Comment:

None.

1st Quarter

Clouds:

Overcast

Wind:

Medium

Seeing Value:

0.00

Seeing Variability:

Sky :

2nd Quarter

Clouds:

Overcast

Wind:

Low

Seeing Value:

0.00

Seeing Variability:

Sky:

3rd Quarter

Clouds:

Overcast

Wind:

Medium

Seeing Value:

0.00

Seeing Variability:

Seeing Source:

Other

Sky:

4th Quarter

Clouds:

Overcast

Wind:

Medium

Seeing Value:

0.00

Seeing Variability:

Sky:

Delete
Edit

Program:

Target of Oportunity:

Time Observed:

0.0

Time Engineering:

9.0

Time lost technical:

0.0

Time lost weather:

0.0

Time lost other:

0.0

Description:

ARCoIRIS Engineering

Primary Investigator:

David James

Email:

djj@ctio.noao.edu [1]

Institution:

CTIO

Instrument:

CTIO 4m ArCoIRIS

Organization:

NOAO

Total Program Time:

Delete [2]
Edit [3]

Add [4]

Total Times	Time Observed	Time Engineering	Time lost technical	Time lost weather	Time lost other	Total Program Time
2016-01-26	0.0	9.0	0.0	0.0	0.0	9