Data model: sdss_tiles

General description: List of SDSS-I, -II tiles that were run through the tiling product, with corresponding geometrical information. This geometrical information is in mangle-type format (see the mangle documentation for a full explanation).

Naming convention: sdss_tiles.fits

Approximate size: 300 kbytes.

File type: FITS

Read by products: sas

Written by products: sas

Required column names:

• XCAPS[3, NCAPS] (float64): direction of cap defining tiling geometry, on unit sphere
• CMCAPS[NCAPS] (float64): size of each cap defining the field
• NCAPS (int32): number of caps (should be 1 for this file)
• USE_CAPS (int32): bitmask containing which caps to actually use
• WEIGHT (float64): weight for polygon (should be 1 for this file)
• STR (float64): area in steradians of polygon
• TILEID (int32): id number of the tile
• CHUNK (int32): chunk number that tile was part of
• RACEN (float64): right ascension of tile center in J2000 deg
• DECCEN (float64): declination of tile center in J2000 deg
• CX (float64): Cartesian coordinate of tile center on unit sphere
• CY (float64): Cartesian coordinate of tile center on unit sphere
• CZ (float64): Cartesian coordinate of tile center on unit sphere
• UNTILED (int16): has this tile been un-tiled?
• EXTINCTION[5] (float32): ugriz extinction in magnitudes at tile center from SFD map
• NTARGETS (int32): number of targets assigned to this tile in tiling

For IDL users, this file is in a "FITS" mangle format, readable by the idlutils routine "read_fits_polygons".