Standard Star Instructions » History » Version 49
Kevin Reil, 11/20/2013 05:13 PM
1 | 14 | Douglas Tucker | h1. Standard Star Instructions |
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2 | 14 | Douglas Tucker | |
3 | 41 | Douglas Tucker | _(Author: Douglas Tucker; Created: 29 Aug 2013; Updated: 28 Sep 2013)_ |
4 | 23 | Douglas Tucker | |
5 | 14 | Douglas Tucker | * Standard star fields are to be observed every evening and morning twilight that appear to be clear, |
6 | 20 | Douglas Tucker | where "clear" is determined by a quick visual inspection of the RASICAM image, of the TASCA image, |
7 | 20 | Douglas Tucker | or (!) of the sky itself. |
8 | 14 | Douglas Tucker | |
9 | 37 | Douglas Tucker | * For evening twilight, the standards can begin about 45 minutes before the end of Astronomical (18-deg) |
10 | 37 | Douglas Tucker | Twilight. If there is a late start, standards can continue until the end of Astronomical Twilight; |
11 | 37 | Douglas Tucker | after the end of Astronomical Twilight twilight, survey science observations must begin. |
12 | 28 | Douglas Tucker | |
13 | 49 | Kevin Reil | * The script DES/defocus_nightly.json should be appended to the last evening standard. No "breaK" is needed. |
14 | 49 | Kevin Reil | The script stays on the last standard field, defocuses, takes a single r-band image and refocuses. Obstac can |
15 | 49 | Kevin Reil | continue on from this point without trouble. If this script *fails* and the camera is out of focus press the |
16 | 49 | Kevin Reil | z-trim button on the ICS screen. |
17 | 48 | Kevin Reil | |
18 | 37 | Douglas Tucker | * For morning twilight, the standards should start 25 minutes after the start of Astronomical (18-deg) Twilight. |
19 | 26 | Douglas Tucker | |
20 | 14 | Douglas Tucker | * If possible, for each twilight period, 3 standard star fields should be observed: one at low airmass |
21 | 14 | Douglas Tucker | (X<1.25), on at medium airmass (X=1.25-1.65), and one at high airmass (X=1.65-2.10). It is generally |
22 | 14 | Douglas Tucker | better to observe the high-airmass field first, since its airmass will be changing the most rapidly. |
23 | 14 | Douglas Tucker | |
24 | 20 | Douglas Tucker | * For half-nights, 1 or 2 fields -- preferably a low-airmass field and a high-airmass field -- should |
25 | 20 | Douglas Tucker | be observed just before switchover. (If only one field, a high-airmass field is preferred.) |
26 | 14 | Douglas Tucker | |
27 | 25 | Douglas Tucker | * The list of DES standard star fields can be found here: [[The Standard Fields]]. Note that they |
28 | 25 | Douglas Tucker | are broken into 3 types: a "Golden" sample, a "Silver" sample, and a "Bronze" sample. The "Golden" |
29 | 25 | Douglas Tucker | sample fields, which have photometrically calibrated standards in all 5 DES filters (grizY) over the full |
30 | 25 | Douglas Tucker | DECam focal plane, take precedence. The "Silver" and "Bronze" either are missing calibrated Y-band |
31 | 25 | Douglas Tucker | data or do not have calibrated standards just yet over the full DECam focal plane. *Always make sure |
32 | 25 | Douglas Tucker | that at least one "Golden" (SDSS) standard star field is observed each clear night.* |
33 | 25 | Douglas Tucker | |
34 | 14 | Douglas Tucker | * For evening twilight, use the *DES/standard/Yzirg* scripts (which start with Y-band and end with g-band); |
35 | 14 | Douglas Tucker | for morning twilight or pre-switchover, use the *DES/standard/grizY* scripts (which start with g-band and |
36 | 14 | Douglas Tucker | end with Y-band). (For those rare nights when we also observe in u-band, please use the corresponding |
37 | 14 | Douglas Tucker | "DES/standard/Yzirgu" and "DES/standard/ugrizY" scripts.) |
38 | 14 | Douglas Tucker | |
39 | 14 | Douglas Tucker | * There are several useful scripts in the StdStarPicker package in the DECamObserver account on observer2, |
40 | 14 | Douglas Tucker | including decamStdFieldsTimeDate.py and decamStdFieldsQueryNextSet.py. |
41 | 14 | Douglas Tucker | |
42 | 22 | Douglas Tucker | * *To get a full list of standard star fields that are in a good position to observe (airmass < 2.10, |
43 | 22 | Douglas Tucker | moon separation > 15 deg, within Blanco horizon limits), use decamStdFieldsTimeDate.py:* |
44 | 14 | Douglas Tucker | |
45 | 16 | Douglas Tucker | <pre><code> |
46 | 14 | Douglas Tucker | source ~/dtucker/bin/setup_StdStarFieldPicker.csh (or .bash if you are using bash shell) |
47 | 14 | Douglas Tucker | |
48 | 14 | Douglas Tucker | decamStdFieldsTimeDate.py --help (for detailed help) |
49 | 14 | Douglas Tucker | decamStdFieldsTimeDate.py --UT=now (for a list accessible right now) |
50 | 14 | Douglas Tucker | decamStdFieldsTimeDate.py --UT='2013/09/17 00:43' (for a list accessible at 00:43UT on Sept 17, 2013) |
51 | 17 | Douglas Tucker | |
52 | 16 | Douglas Tucker | </code></pre> |
53 | 1 | Douglas Tucker | |
54 | 18 | Douglas Tucker | * *To get a preferred triad of standard fields -- a low-airmass field, a medium-airmass field, and a |
55 | 18 | Douglas Tucker | high-airmass field -- for a given time and date, use decamStdFieldsQueryNextSet.py:* |
56 | 1 | Douglas Tucker | |
57 | 1 | Douglas Tucker | <pre><code> |
58 | 17 | Douglas Tucker | source ~/dtucker/bin/setup_StdStarFieldPicker.csh (or .bash if you are using bash shell) |
59 | 17 | Douglas Tucker | |
60 | 14 | Douglas Tucker | decamStdFieldsQueryNextSet.py --help (for detailed help) |
61 | 1 | Douglas Tucker | decamStdFieldsQueryNextSet.py --UT=now (for a triad accessible right now) |
62 | 14 | Douglas Tucker | decamStdFieldsQueryNextSet.py --UT='2013/09/17 00:43' (for a triad accessible at 00:43UT on Sept 17, 2013) |
63 | 1 | Douglas Tucker | |
64 | 1 | Douglas Tucker | (Warning: decamStdFieldsQueryNextSet.py will output a default json file, "stdstar.json". Just ignore it.) |
65 | 18 | Douglas Tucker | |
66 | 14 | Douglas Tucker | </code></pre> |
67 | 1 | Douglas Tucker | |
68 | 41 | Douglas Tucker | * *For simplicity, look-up tables -- one for each month of DES Year 1 Operations -- listing the preferred |
69 | 41 | Douglas Tucker | triad for each 15-min interval throughout each night, can be found here:* |
70 | 41 | Douglas Tucker | |
71 | 41 | Douglas Tucker | > * "*listOfStdsByUT.Sept2013.txt*":https://cdcvs.fnal.gov/redmine/attachments/11984/listOfStdsByUT.Sept2013.txt |
72 | 1 | Douglas Tucker | |
73 | 41 | Douglas Tucker | > * "*listOfStdsByUT.Oct2013.txt*":https://cdcvs.fnal.gov/redmine/attachments/12675/listOfStdsByUT.Oct2013.txt |
74 | 1 | Douglas Tucker | |
75 | 41 | Douglas Tucker | > * "*listOfStdsByUT.Nov2013.txt*":https://cdcvs.fnal.gov/redmine/attachments/12676/listOfStdsByUT.Nov2013.txt |
76 | 25 | Douglas Tucker | |
77 | 41 | Douglas Tucker | > * "*listOfStdsByUT.Dec2013.txt*":https://cdcvs.fnal.gov/redmine/attachments/12677/listOfStdsByUT.Dec2013.txt |
78 | 21 | Douglas Tucker | |
79 | 1 | Douglas Tucker | > * "*listOfStdsByUT.Jan2014.txt*":https://cdcvs.fnal.gov/redmine/attachments/12678/listOfStdsByUT.Jan2014.txt |
80 | 1 | Douglas Tucker | |
81 | 1 | Douglas Tucker | > * "*listOfStdsByUT.Feb2014.txt*":https://cdcvs.fnal.gov/redmine/attachments/12680/listOfStdsByUT.Feb2014.txt |
82 | 46 | Douglas Tucker | |
83 | 46 | Douglas Tucker | |
84 | 46 | Douglas Tucker | * _*You can also just run the the kentools commands "ephem" and "standards" described in the [[Introduction to kentools]] |
85 | 47 | Douglas Tucker | to find the appropriate triads of standard fields to observe. This is usually the simplest option.*_ |
86 | 21 | Douglas Tucker | |
87 | 21 | Douglas Tucker | h2. Attachments |