Date:
Saturday, March 15, 2014
Telescope:
CTIO Blanco 4-m
Submitter:
David James
Submitter Email:
Observer Support:
David James
Night Assistant:
Alberto Alvarez
Also Present:
Tom Diehl, Curtis Weaverdyck, Manuel Hernandez, Javier Rojas, Roberto T. (by telephone)
Problems:
So, our night of post-DECam-engineering shutdown observations went fairly well, with an admixture of stunning successes (new u-filter flats and the first science image using the new VR-filter) and a few niggly failures.
There were a series of intermixed errors/mis-communications that are hard to dis-entangle over the course of the night (see elogs #173330, #173342, #173360, #173423, #173433 and #173494), although a summary of the effects of these errors is discussed in elog #173423.
Unfortunately, several pathological errors in the aberration mapping script complicated the resolution of an apparent series of SISPI problems. While many of the SISPI failures were actually due to the aberration observation scripting faults, there does appear to be a genuine problem in the way SISPI and the guider (GSC role) are communicating.
Unfortunately, there was not enough time for Klaus to resolve the VR-filter LUT problem.
Eventually, with assistance from Alberto Alvares, we managed to make the Aberration Mapping script work, but a few observation positions were commanded that caused M1's active optics system 4MAP) to crash. while formally the script was completed by the time the Sun was rising (Sun's altitude was about -14 degrees by the end), there is no doubt that we'll have to re-execute the observations again this evening (see elog #173433 & #173494).
Unfortunately, several pathological errors in the aberration mapping script complicated the resolution of an apparent series of SISPI problems. While many of the SISPI failures were actually due to the aberration observation scripting faults, there does appear to be a genuine problem in the way SISPI and the guider (GSC role) are communicating.
Unfortunately, there was not enough time for Klaus to resolve the VR-filter LUT problem.
Eventually, with assistance from Alberto Alvares, we managed to make the Aberration Mapping script work, but a few observation positions were commanded that caused M1's active optics system 4MAP) to crash. while formally the script was completed by the time the Sun was rising (Sun's altitude was about -14 degrees by the end), there is no doubt that we'll have to re-execute the observations again this evening (see elog #173433 & #173494).
Program:
Proposal:
2013A-9999
Target of Oportunity:
No
Time Observed:
0.0
Time Engineering:
9.5
Time lost technical:
0.0
Time lost weather:
0.0
Time lost other:
0.0
Description:
DECam Engineering
Primary Investigator:
Alistair Walker
Email:
Institution:
CTIO
Instrument:
CTIO 4m DECam
Organization:
NOAO
Total Program Time:
9.5
| Total Times | Time Observed | Time Engineering | Time lost technical | Time lost weather | Time lost other | Total Program Time |
|---|---|---|---|---|---|---|
| 2014-03-15 | 0.0 | 9.5 | 0.0 | 0.0 | 0.0 | 9.5 |
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So, as in described in elogs #173175 and #173180, new 365-nm LEDs have been installed into the DECal projector units. Some simple flat-field test exposures (elog #173186 and #173193) after dinner showed that the flux in the u-filter was VERY much improved ...> enough to turn down the power in the 365-nm LED from 80% to 70% (see attached image for flatfield check results with 25-second u-flats).
While not plotted on the FlatFieldCheck image, I also took the first VR-filter flatfield images, which qualitatively looked excellent (elog #173196).
Once we opened-up, I observed a few fields near to the bright southern star Canopus, which Steve K. and Tom D. had identified as having being observed in DES-YR1, and should allow us to test the effects of the anti-reflection paint/coatings that were applied to various surfaces/components inside DECam this week --> see elog #173244 and #173253 for details.
First science images using the new VR-filter were obtained (see elog #173319), and several multi-exposure images were taken to test linearity and background rates (in high Moonlight). I choose the Orion Nebula Cluster (M42) as first light object, and the results are stunning !