IPP Progress Report for the week 2009.09.13 - 2009.09.18

(Up to IPP Progress Reports)

Eugene Magnier

Heather Flewelling

Bill Giebink

Paul Price

• Detection efficiency: merged branches/pap into trunk, r25383.
• PS1SC:
  • Set up nightlogs@… list
  • Organising UK tour
  • Retrieved and sent dravg archive
• Stacking:
  • Everything was getting rejected. Turned off "additional variance" in pmStack, and get decent rejections now. This is not well understood yet, but may be connected with a change made a month ago removing the "variance factor" terms, or renormalising the image subtraction chi^2.
  • Can identify bad images using the iq statistics calculated in psphotImageQuality.c: iq_m2, iq_m2_uq-iq_m2_lq, iq_m3 and iq_m4 are useful quantities.
  • Sent Nigel and Peter a dump of ThreePi data from June/July that should be useful for determining good cuts on these quantities.
  • High-frequency structure in kernels caused by minimum ISIS width = 1 (FWHM, not sigma!): fixed ppSub recipe
  • Increased rejection threshold (COMBINE.REJ) to 2.5 from 2.0 standard deviations.
  • Using a given analytic PSF instead of that produced by pmPSFEnvelope produces reasonable results for the stack. Attempting to correlate resultant convolution kernels with iq statistics.
• Fixed fuzz of FITS images so that expectation values are preserved (trunk@25439), after help from ​http://fits.gsfc.nasa.gov/registry/tilecompression.html

Bill Sweeney

Chris Waters