ti Files

The "ti" files (eg. tiBest.sample8.fits) contains the global tiling information for all of the targets. These files are created using the following steps:

• The results of tiling for each chunk are created when tiling is run. This sets the following flags:
  • tileid: id of the tile the target was assigned to (-1 if none)
  • mask: flag describing happened to the target during the tiling process (-1 if target was never tiled --- think about it, it happens for the "Best" sample). The bits are:
    • 2^0: assigned to a tile
    • 2^1: a decollided target
    • 2^2: covered by a tile
• These results are combined by grouping all the targets with a linking length of 0.5 arcsec, and picking only one target from each group. This takes care both of objects which are identified twice as primary targets (due to photo/target/opdb bugs) and targets which have been tiled twice. Only one tileid is kept as the official tile; the masks are ORed.
• Given this unique, global list, we set the parameters:
  • firstboundary: this refers to the first boundary region in the appropriate tiling boundary list, this is a concatenation of all of the boundary regions which make up each tiling chunk
  • overlap: otherwise known as a "sector", this refers to which unique set of tiles in the sector list this falls in (note that a tile cannot cover an area which was not in the chunk to which the tile belonged, and the overlap definitions take this into account)
  • collisiongroup: which 55 arcsec collision group the targets are in (note that this is *reset* here, so it will be different in general than in the full tiling results)
• Finally, I match the list to the tsObj files. Entries are made for all tsObj tiled targets; when tiling data is not available all zeros are entered. Tiling information for non-tiled targets (eg., in the Best version files) are appended to the end of the file.

The photometric parameters listed in these files (run, rerun, psfmag, etc) ALWAYS refer to the drilling version (even in tiBest) since this is what is in the tiling files.

For reference, here is the fits header:

XTENSION= 'BINTABLE'           /Binary table written by MWRFITS                
BITPIX  =                    8 /Required value                                 
NAXIS   =                    2 /Required value                                 
NAXIS1  =                  100 /Number of bytes per row                        
NAXIS2  =               220550 /Number of rows                                 
PCOUNT  =                    0 /Normally 0 (no varying arrays)                 
GCOUNT  =                    1 /Required value                                 
TFIELDS =                   19 /Number of columns in table                     
COMMENT                                                                        
COMMENT  *** Column formats ***                                                
COMMENT                                                                        
TFORM1  = 'J       '           /                                               
TFORM2  = 'J       '           /                                               
TFORM3  = 'J       '           /                                              
TFORM4  = 'J       '           /                                               
TFORM5  = 'J       '           /                                               
TFORM6  = 'J       '           /                                               
TFORM7  = 'D       '           /                                               
TFORM8  = 'D       '           /                                               
TFORM9  = 'J       '           /                                               
TFORM10 = 'J       '           /                                               
TFORM11 = 'J       '           /                                               
TFORM12 = 'J       '           /                                               
TFORM13 = 'J       '           /                                               
TFORM14 = 'J       '           /                                               
TFORM15 = 'J       '           /                                               
TFORM16 = 'J       '           /                                               
TFORM17 = 'E       '           /                                               
TFORM18 = 'E       '           /                                               
TFORM19 = '5E      '           /                                               
COMMENT                                                                        
COMMENT  *** Column Names ***                                                  
COMMENT                                                                        
TTYPE1  = 'RUN     '           /                                               
TTYPE2  = 'RERUN   '           /                                               
TTYPE3  = 'COL     '           /                                               
TTYPE4  = 'FIELD   '           /                                               
TTYPE5  = 'ID      '           /                                               
TTYPE6  = 'TID     '           /                                               
TTYPE7  = 'RA      '           /                                               
TTYPE8  = 'DEC     '           /                                               
TTYPE9  = 'PRIORITY '          /                                               
TTYPE10 = 'TILEID  '           /                                               
TTYPE11 = 'MASK    '           /                                               
TTYPE12 = 'COLLISIONGROUP '    /                                               
TTYPE13 = 'FIRSTBOUNDARY '     /                                               
TTYPE14 = 'OVERLAP '           /                                               
TTYPE15 = 'PRIMTARGET '        /                                               
TTYPE16 = 'SECTARGET '         /                                               
TTYPE17 = 'OBJC_ROWC '         /                                               
TTYPE18 = 'OBJC_COLC '         /                                               
TTYPE19 = 'PSFMAG  '           /                                               
COMMENT                                                                        
COMMENT  *** End of required fields ***                                        
COMMENT                                                                        
END