Closed sbailey closed 8 years ago
Q: Are we going to calculate 'KNOWN' bit in desi-target?
Q: Are we going to calculate 'KNOWN' bit in desi-target?
I think the answer is "eventually yes". This would be handled as another input stream of known targets that would be used on a case by case basis for each bit. People who have actually done this before for SDSS should be consulted for what worked and didn't work.
I just had a very useful chat with Nathalie and David S. A few things came up:
It should not be LRG = (LRG_NORTH or LRG_SOUTH)
since that effectively creates 3 regions of the survey (north only, south only, overlap). It should be LRG = (LRG_NORTH and DEC>=x) or (LRG_SOUTH and DEC<x)
since that defines only 2 regions, while still allowing comparison of selection bits in the overlap. The concept of "DEC<x" could be a more complicated geometry if needed.
Goals for the target selection flags overall:
Open questions:
Options:
Creating a ticket so we don't forget about it. We need to reserve target bits for the Bright Galaxy Survey (BGS), the Milky Way Survey (MWS), sky fibers (SKY), F-type standard stars (FSTD), and White Dwarf standard starts (WDSTD).
From Jeremy Tinker:
Connie Rockosi indicated that the MWS may want to group targets by their proper motion in order to use different priorities. Let's reserve 5 bits, and maybe in a different range to so that we can expand them a bit more if needed.
Also: we need to resolve how targeting bits will be handled for South (DECaM-based) vs. North (Bok+Mosaic based) vs. overlap regions. One option is to define separate LRG_SOUTH and LRG_NORTH bits, perhaps with a 3rd convenience LRG big that is just the logical OR of LRG_SOUTH and LRG_NORTH. Ditto for ELG, etc.
Assigning to @moustakas since I definitely want his input on this, though others are also welcome to contribute.