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MJD56193 Standard Star Observations

Status as of 2012 September 24

  • Standard stars should be primarily on CCD S4.
  • Location of raw data for this night at Fermilab: /blue-orch/DTS/src/20120922/src/
  • Location of reduced data this night at Fermilab for CCD S4: /blue-orch/dtucker/DECam/20120922/Reduced (in progress)

Status as of 2012 September 25

  • I am processing the data using a variation of some python scripts used in PreCam processing. These updated scripts can be found on the Fermilab des cluster here at /usrdevel/dp0/dtucker/dtuckerCode/PythonScripts/ImageProcessing/DECam. NOTE: these updated scripts might not be fully debugged.
  • Here is a heavily stretched, zoomed-in plot of the master bias for CCD N4. The overscan has been subtracted on a row-by-row basis. Strange low-amplitude chevron pattern, perhaps similar (but much weaker) to what was seen using a DECam 2kx2k CCD on the CTIO-1m telescope a couple years ago. Is this a real effect, or a bug/"feature" in the updated python scripts (TBD)? Has anyone else seen this? (The master bias in question can be found on the Fermilab des cluster here: /blue-orch/dtucker/DECam/20120922/Reduced/Bias.N4.fits.) Update (2012/9/26): I showed this to Huan Lin and to Steve Kent, and they each indicated that this chevron pattern has been seen in the DECam data and it likely due to the running of the ion pump.

Zoomed-in Master Bias from MJD56193

  • Here are the u-band overscan-corrected, bias-subtracted master flats for the 2 central CCDs (N4 and S4). Note the evidence for the pupil ghost. Update (2012/9/26): This is not a pupil ghost but a "donut" (lower light level in the center); thanks to Steve Kent for pointing this out!

Master u-band flats (central CCDs N4 and S4)

  • Here is a figure showing the master flats for CCDs N4 and S4 side-by-side for each of the DECam filters (ugrizY). The pupil ghost donut is not as noticeable visible in the the non-u-band master flats (Updates: 2012/9/26).

ugrizY master flats for MJD56193

Status as of 2012 October 7

  • Astrometry with the home-brewed pipeline was going to be a bit of a pain with the early data I've been analyzing; so spent much of the last couple weeks learning how to run the DESDM standalone pipeline, especially on a subset of CCDs but over multiple exposures.
  • Have processed central 10 CCDs for all the data at Fermilab from the night of 2012-09-22 (there may be some exposures missing for this night from the Fermilab archive, but good enough for now). (Many, many thanks to Brian Yanny for all the help!)
  • Also working on a standalone version of he DESDM Photometric Standards Module (PSM) -- a version that does not depend on the DESDM database. This will be the workhorse for many of my analyses. Running the standalone pipeline on the 2012-09-22 data has been of great help in understanding the directory and file structure the standalone PSM needs to deal with.
  • A bash script that does cross-matching of the data with a standard star catalog using STILTS tskymatch2 command does a good (and quick) job; now adding that utility into a more generally usable python script to be added to the SV redmine svn respository.