Changes between Version 4 and Version 5 of PS1_MD04_RefStack

Timestamp:

Jun 20, 2010, 12:05:47 PM (16 years ago)

Author:

eugene

Comment:

--

PS1_MD04_RefStack

@@ -102 +102 @@
 I then supplied this offset to the database by editing the dvo photcode table, extracted with {{{photcode-table -export (file) -D CATDIR (catdir)}}} and imported with {{{photcode-table -import (file) -D CATDIR (catdir)}}}.  Changing the photcode table immediately changes the interpretation of the measurement magnitudes, since the calibrated values are calculated from the instrumental magnitudes on the fly.  For the average magnitudes, however, it is necessary to recalculate the averages.  There is not currently a tool to update the average magnitudes and the photcode table in a single consistent way (though this is a reasonable tool to create).  It should have been possible to supply this offset to the high-quality photometry database and update the averages based on only that subset of the data.  However, to be sure everything was consistent, I simply updated the full-scale databases, and then recreated the high-quality ones from the original databases.
 
+=== Processing the Images ===
+
+Once the MD04 reference dvo database was available, it was now possible to use it for the data processing.  I copied the database to the Maui cluster (actually a copy on several of machines to reduce the loading), and created an alternate reduction class in which I defined a psastro recipe with the new reference database as the calibration source.  The was this is currently defined in the recipe system is a bit cumbersome; we need to consider ways of making this more flexible.  One particular inconvenience comes from the definition of the average photcodes.  The psastro recipe needs to associate the filter being processed with a specific average photcode from the reference database.  The synthetic grizy database uses average names of the form g_SYNTH, and these are listed in the default recipe for gpc1 as a MULTI block.  With our current metadata parsing, it is not possible to have a recipe which overrides the values in the MULTI block; new values simply supplement the set of existing values, leading to confusion.  To make the system work for now, I changed the new reference db average photcodes to have the same form as the synthetic db.  
+