Release Notes for v2.2

Major Physics upgrades:

• Throughputs updated to 1777 completely (this now includes Y4, an update to the mirror reflectivity curve, and making the detector A/R coat consistent with implied QE curve)

• Moon SED had dark sky contamination (we knew about this for PT1.1 so skillfully avoided making the background too high in the redder bands, but making this consistent with alternative calculations to within a factor ~3); also added more accurate wavelength dependence of rayleigh scattering (but not Mie scattering) so redder light from moon isn't scattered as far

• Switched to Optics version 3.3 from 3.2 (changes camera optics mainly)

• CCD back change to 20% reflectance on backside and adjusting A/R coat accordingly

• Cadence (15-2-15 due to OpSim, keep same?)

• Somewhat smaller optics perturbations (~25%) to be more SRD consistent

Bugs or Inconsistencies:

• Redshift not being used properly (fixed)

• Dust parameters not being used properly (fixed)

• Flux normalization was hacked to correct for catalog deficiencies (fixed)

• Some UV light not propagating fully (didn't matter before, but fixed)

• Wavelength-dependent effect of screen inner roll off (added)

• Simulation of background & flats inconsistent with vignetting profile in raytrace (fixed)

• Tracking pattern continues through exposures (fixed, negligible?)

• Wavelength interpolated from SEDs

• Unified random number generator with better one

• Time in the header was wrong & various bad header key words

• Many small things but not expecting any of them to do anything visible in images

Major efficiency enhancements:

• Bright star speed up algorithm changed completely: should make images look better & run faste

• Some other simplifications & speed ups (particularly dust & optics

• Ghosts simulations now do not add enormous simulation time (but we are going to keep ghosts off because we have not tested it enough)

• Tons of code reorganization which should have no (or positive) effect

• Most of the reorganization was occuring while we had pieces of the validation framework in place, so some of the major observable properties of images (photometric throughput & PSF shape) were constantly being checked

• Gzipping catalogs & SEDs to reduce I/O

• Scripts unified for darks, flats, biases

• Validation framework written & applied for ~50% of tasks