DECam Tools

RASICAM [2] -- A radiometric all-sky infrared camera has been built to monitor night sky conditions to support DECam observations (i.e. detect and quantify the optical depth of clouds, and determine photometricity).

• RASICAM on YouTube [3]

SCRIPTS EDITOR [4] -- the ScriptsEditor tool can be used to write exposure scripts for DECam.  This is a stand alone code that can easily be installed on your workstation.  Python (with Tkinter support) is the only requirement.

Steve Kent Tools--at-telescope tools

How to use kentools:
1.  Login as DECam Observer on obsever2
2.  Type "observer"
Make use of the list commands
data  cd to /data_local/
inventory n  (data from b days ago, default 0)
load (exp num>  [ccd id]   (default is S4) )
focus  (click on first in the sequence)
seeing  (click on star, does radial plot)
offset  (displays N4, click on star, gives offset to the fiducial pixel 1024,2048; for pointing map)
command  (type this list)
camFbsPlot  (This shows 1.  the shape of the stellar ellipticity for every DECam CCD, 2.  ellipticity with mean ellipticity subtracted 3.  the relative fwhm to the mean.  This command takes a while to run.)
seeingall  (This gives a seeing estimate using the 8 inner most CCDs--you don't have to click on a star.)
center (This command checks the NOMAD catalogue to determine how far away the telescope is pointing in RA and DEC.  The delta RA and delta Dec values that are returned can be entered in the observer console, exposure control fields to center the telescope.)
bigload (Displays all 62 CCDs with a quick bias subtraction and decimated by a factor of 8).
boreset  (Returns offsets that are the position of the star relative to the center of the focal plane array.)
tim (Operates like "center" but uses the telescope coordinates TELRA and TELDEC instead of the target coordinates.  The outputs are of the form "tel - truth" - you would subtract these from the indicated telescope coordinates to get the actual position on the sky).

DECam Schematics:
Courtesty of Dr. Andrea Kunder

[5]
The five lenses in the DECam imager, designed to provide a large field or view, high throughput,
and good image quality. Four of the five lenses will be mounted in individual adjustable cells with
flexure systems and lens C5 will be mounted in a cell with o-rings for the vacuum seal with the dewer.
This configuration is capable of delivering sub-arcsecond images. The total length of the camera from
C1 to the focal plane is ~1.9 m, and the C1 lens is ~1 m in diameter.

[6]
Here is the Blanco telescope shown cut by half along the long axis showing the
optical path to the DECam imager. The DECam is in the prime focus cage
(the black box in the top of the photo).

References

"The Dark Energy Survey (DES) & Camera (DECam)" [7] - slides from talk by Tom Diehl at January 2012 AAS meeting.
NOAO Newsletter March 2011, page 17 [8]
NOAO Newsletter March 2010, page 10 [9]
NOAO Newsletter September 2010, page 11 [10]
"Status of the dark energy survey camera (DECam) project" [11] - Flaugher et al. 2010, SPIE Vol. 7735.
"A radiometric all-sky infrared camera (RASICAM) for DES/CTIO" [12] - Lewis et al. 2010, SPIE Vol. 7735.
"The Dark Energy Camera (DECam)" [13] - DePoy et al. 2008, SPIE Vol. 7014.
"The Dark Energy Camera (DECam)" [14] - Honscheid et al. 2008, 34th Int'l Conf. on High Energy Phys.
"The Dark Energy" by the Dark Energy Survey Collaboration, astro-ph/0510346 [15]