Changes between Version 6 and Version 7 of stacking_coverage.20130307

Timestamp:

Apr 16, 2013, 4:54:43 PM (13 years ago)

Author:

watersc1

Comment:

--

stacking_coverage.20130307

@@ -30 +30 @@
 
 We can now plot up the data and quadratic fits to validate their quality.  These plots clearly point that the large chi!^2 values being used to reject input exposures at the PSF matching stage are caused by poor quadratic fits to relatively well constrained data.  This supports the "by-eye" assessment that the images being rejected do not look like they should be rejected.
+
+Comparing polynomial fits from IPP with external code, it appears that the assumption that chisq(flux) is a well-behaved quadratic function is not necessarily true.  Fitting a quadratic to log10(chisq(log10(flux))) looks to provide a better fit to the data trend.
 
 ||Image || Plot ||