IPP Progress Report for the week 2010.07.19 - 2010.07.23

(Up to IPP Progress Reports)

Eugene Magnier

I was out on Jury duty for most of 2 days this week. I made some progress on two fronts: relastro and extended source analysis. Bill discovered a problem with relastro in how it monitors the fit quality and how it handles poor fits. It attempts to watch for any fitted source position which deviates by more than a small allowed amount -- evidence that the fit for the chip was allowed to run-away in some region -- and then remove the offending image. It turned out that this test and fix resulted in the database being re-loaded many times for each repaired image. Not very efficient. I re-worked the test to use a grid of test points mapping the area of the image where real sources exist. This allows the quality check to be done before the data is written in the first pass, so that failed images can be immediately reverted to their original fit. In testing this analysis, I discovered a bug with the conversion between the internal representation of the astrometric solution (as a standard polynomial) and the WCS representation: the reference pixel is normally set to the telescope boresite, but the non-linear terms may sometimes be large enough that the solution of this position is does not easily converge. I modified the assumptions in the code to allow this conversion to WCS terms to reset the reference pixel to a pixel on the image.

For the extended source analysis work, I have finished modifications to the psf-convolved fitting process to allow a grid search of the sersic index parameter. This required some modest re-working of the APIs to allow some additional flexibility. I have also measured the relationship between the measured moments and the guess scale length as a function of the sersic index, making the initial guess more accurate. At this point, I'm happy with the results of this analysis, but not happy with the speed. The PSF-convolved fitting is too slow, so I intend to make some fairly easy optimizations (convert the convolutions to FFTs and carry the FFT of the psf image during the fit).

Serge Chastel

  • IppMonitor: Working on scripts that will display summaries.
  • PSPS: read documentation/code of the various PSPS components.

Heather Flewelling

  • detrend work
    • fixed dettool so that -definebytag works in -mode master. This is checked in on the trunk.
    • launched det_id 340 - subset of 'good' exposures, but still has problems with bad background residuals.
    • launched det_id 341 - subset of 'good' exposures, but with only 100s exposure, still had problems with bad background residuals
    • made plots/analysis of det_id 325 and 340
  • czar on monday & tuesday
  • 3 days vacation ( wed - fri)

Roy Henderson

  • PSPS
    • successfully loaded an MD field exposure with Sue: various problems worked through at both ends
    • data issues:
      • looked into duplicate-objIDs-on-one-exposure problem: couldn't confirm
      • looked into issue with certain detections within 0.5 arcsecs being assigned different objIDs: pulled smfs, generated mosaicked images etc.
  • IPP
    • ippToPsps:
      • wrote perl module/classes for database access (to gpc1 and ippToPsps Dbs) for ippToPsps
      • fixed problem with flux errors for detections
    • czartool:
      • czardb now has history of each pantasks server status, i.e. when it was running and when it was alive
      • finished plotting functionality: can now plot all stages as a time-series for a given label, or all labels
      • numerous other changes which I checked into svn for first time
      • adapted ippMonitor czartool to use czarDb and not gpc1. Much faster
      • all czartool pages now on one page for convenience
    • Czar on Wednesday

Bill Sweeney

  • shepherded the new MD 8, 9, and 10 reference stacks through processing. With so many inputs there is a high probability of nfs type errors so these need to be watched.
  • spent some time debugging a memory corruption problem in the cfitsio gzip compression code. It is repeatable but does not happen with the latest version of cfitsio. We have frozen on a previous version. The plan is to create a simple test case to demonstrate the problem. Turning off compression on the few skycells that trigger the problem is an acceptable workaround.
  • Dealt with some postage stamp server nastiness triggered by innocent user flooding us with requests on a less tested part of the system.
  • Added some more information to the postage stamp server status page http://pstamp.ipp.ifa.hawaii.edu/status.php This gives users some feedback that we actually did get their requests.
  • extracted the smf file names that were included in the ThreePi?.V1 dvo database to prepare to run setphot on it to set the calibrated zero points.
  • can't recall where the rest of the time went.

Chris Waters

  • Linearity: created comparison plots for cell-level linearity between IPP and Camera team data. Improved measurements and metrics, illustrating that most cells are linear at reasonably high flux levels, but that there are deviations at lower flux. Generated plots showing that the non-linear edge rows and columns correlate with one set of detectors.
  • OTA11: confirmed from running microtest3 configuration flat data through the CTE mask generation code that the CTE problems on this detector can most likely be repaired.
  • detectability server: Began making changes to improve efficiency and to support a new version of the request format as requested by users.