drizzle, astrometry

talk, talk, talk!

I talked to Schlegel at length about the conceptual problems with drizzle, and reiterated my concerns that (a) it does not optimize a scalar objective function; ie, the image it produces is not the "best" in any conceivable sense; and (b) philosophically, it treats the telescope as a photon bucket, not a device that measures the intensity. This latter problem is subtle, but if you treat the detector as a flux collector, you have to worry about "flux conservation" and "gaps in the detector" etc, but when you think of it as device that measures the intensity field, you just have to determine each pixel's "beam" and then note that each measurement pixel constrains the beam-convolved intensity map. Of course, drizzle exists, and my ideas are vapor-ware, or maybe bar-ware, since they are just polemics shouted in bars.

I talked to Sam and Morad about the current status of the astrometry project, and we heard that the indexing job we started on Friday finished in an hour (which is good) and we checked some numbers relating to methodologies for determining, at test time, which index matches are correct, and which are flukes.