========================== fiberassign-TILEID.fits.gz ========================== :Summary: The fiberassign file contains the fiber positioner configuration information for each exposure: what fiber is placed where, what target that is, etc. :Naming Convention: ``fiberassign-TILEID.fits.gz``, where TILEID is the zero-padded 6-digit tile ID. Some early versions were not compressed. :Regex: ``fiberassign-[0-9]{6}\.fits\.gz`` :File Type: FITS, 5 MB Contents ======== ====== ===================== ======== =================== Number EXTNAME Type Contents ====== ===================== ======== =================== HDU0_ PRIMARY IMAGE Keywords only HDU1_ FIBERASSIGN BINTABLE Target assignments for each fiber HDU2_ SKY_MONITOR BINTABLE Sky location for the 20 sky monitor fibers used by the ETC HDU3_ GFA_TARGETS BINTABLE Selected star for the ETC / GUIDE / FOCUS HDU4_ TARGETS BINTABLE List of targets that are reachable by a positioner HDU5_ POTENTIAL_ASSIGNMENTS BINTABLE All possible (TARGETID, FIBER, LOCATION) assignments ====== ===================== ======== =================== FITS Header Units ================= HDU0 ---- EXTNAME = PRIMARY No data, but some useful header keywords. Required Header Keywords ~~~~~~~~~~~~~~~~~~~~~~~~ .. collapse:: Required Header Keywords Table .. rst-class:: keywords ============= ======================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================= ===== ======= KEY Example Value Type Comment ============= ======================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================= ===== ======= TILEID 4403 int Tile ID TILERA 170.239 float [deg] Tile Right Ascension TILEDEC -7.093 float [deg] Tile Declination FIELDROT 0.0210480650645507 float [deg] Field rotation FA_PLAN 2022-07-01T00:00:00.000 str [UTC] Plan field rotations for this date FA_HA -6.72 float [deg] Design Hour Angle FA_RUN 2022-01-03T17:00:31+00:00 str [UTC] Date of the loaded Focal Plane state FA_M_GFA 0.4 float [mm] Margin around GFA keep-out polygons FA_M_PET 0.4 float [mm] Margin around petal-boundary keep-out polygons FA_M_POS 0.05 float [mm] Margin around positioner keep-out polygons REQRA 170.239 float [deg] Tile Right Ascension REQDEC -7.093 float [deg] Tile Declination FIELDNUM 0 int Not used, always zero FA_VER 5.4.0 str Fiberassign code version FA_SURV main str Survey of origin of the targets FAFLAVOR maindark str String composed of the SURVEY and the PROGRAM DESIROOT /data/datasystems str DESI_ROOT environment variable path GFA DESIROOT/target/catalogs/dr9/1.1.1/gfas str Path to the input GFA targets MTL DESIROOT/survey/ops/surveyops/trunk/mtl/main/dark str Path to the primary targets ledgers SCND DESIROOT/target/catalogs/dr9/1.1.1/targets/main/secondary/dark/targets-dark-secondary.fits str Path to the secondary targets static catalogs SCND2 DESIROOT/target/catalogs/dr9/1.1.1/targets/main2/secondary/dark/main2targets-dark-secondary.fits str Path to the secondary targets static catalogs SCNDMTL DESIROOT/survey/ops/surveyops/trunk/mtl/main/secondary/dark str Path to the secondary targets ledgers SKY DESIROOT/target/catalogs/dr9/1.1.1/skies str Path to the sky targets SKYSUPP DESIROOT/target/catalogs/gaiadr2/1.1.1/skies-supp str Path to the supp-sky targets TARG DESIROOT/target/catalogs/dr9/1.1.1/targets/main/resolve/dark str Path to the primary targets static catalogs TOO DESIROOT/survey/ops/surveyops/trunk/mtl/main/ToO/ToO.ecsv str Path to the Target-of-Opportunity catalog FAARGS --doclean n --dr dr9 --dtver 1.1.1 --gaiadr gaiadr2 --goaltime 1000.0 --ha -6.72 --hdr_faprgrm dark --hdr_survey main --log_stdout False --lookup_sky_source ls --margin_gfa 0.4 --margin_petal 0.4 --margin_pos 0.05 --mintfrac 0.85 --mtltime 2022-01-13T18:13:09+00:00 --nosteps qa --pmcorr n --pmtime_utc_str 2022-01-14T10:13:28+00:00 --program DARK --rundate 2022-01-03T17:00:31+00:00 --sbprof ELG --sky_per_petal 40 --sky_per_slitblock 1 --standards_per_petal 10 --steps tiles,sky,gfa,targ,scnd,too,fa,zip,move,qa --survey main --svntiledir /data/tiles/SVN_tiles --tiledec -7.093 --tileid 4403 --tilera 170.239 --worldreadable True str fba_launch command arguments OUTDIR /data/datasystems/target/fiberassign/holding_pen/ str Folder where the fba_launch outputs are written SURVEY main str Survey of origin of the targets NOWTIME 2022-01-14T10:13:28+00:00 str [UTC] Date of the fba_launch call RUNDATE 2022-01-03T17:00:31+00:00 str [UTC] Date of the loaded Focal Plane state PMCORR n str Is proper-motion correction applied for stars? PMTIME 2022-01-14T10:13:28+00:00 str [UTC] Used current time, if proper-motion correction is applied FAPRGRM dark str Program to which this tile belongs MTLTIME 2022-01-13T18:13:09+00:00 str [UTC] Date used to read the ledgers OBSCON DARK|GRAY|BRIGHT|BACKUP str Allowed observing conditions for this tile GOALTIME 1000.0 float [s] Aimed EFFTIME_SPEC GOALTYPE DARK str Sky conditions used for some noise estimation EBVFAC 1.08401875659818 float 10.0 ** (2.165 * median(EBV) / 2.5)) SBPROF ELG str Source profile used for some noise estimation MINTFRAC 0.85 float Fraction of GOALTIME to be reached by EFFTIME_SPEC to consider the tile has completed FASCRIPT /software/datasystems/desiconda/20200924/code/fiberassign/5.4.0/bin/fba_launch str Path to the fba_launch used script SVNDM 138481 str DESIMODEL/data svn revision number SVNMTL 1083 str DESI_SURVEYOPS/mtl svn revision number LKSKYSRC [1]_ ls str Photometric survey used for the sky look-up table for the stuck fibers ============= ======================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================================= ===== ======= .. [1] Optional Empty HDU. HDU1 ---- EXTNAME = FIBERASSIGN The target assignments for each fiber of this tile. Required Header Keywords ~~~~~~~~~~~~~~~~~~~~~~~~ .. collapse:: Required Header Keywords Table .. rst-class:: keywords ======== ========================= ===== ======================= KEY Example Value Type Comment ======== ========================= ===== ======================= NAXIS1 293 int width of table in bytes NAXIS2 5000 int number of rows in table TILEID 4403 int Tile ID TILERA 170.239 float [deg] Tile Right Ascension TILEDEC -7.093 float [deg] Tile Declination FIELDROT 0.0210480650645507 float [deg] Field rotation FA_PLAN 2022-07-01T00:00:00.000 str [UTC] Plan field rotations for this date FA_HA -6.72 float [deg] Design Hour Angle FA_RUN 2022-01-03T17:00:31+00:00 str [UTC] Date of the loaded Focal Plane state FA_M_GFA 0.4 float [mm] Margin around GFA keep-out polygons FA_M_PET 0.4 float [mm] Margin around petal-boundary keep-out polygons FA_M_POS 0.05 float [mm] Margin around positioner keep-out polygons REQRA 170.239 float [deg] Tile Right Ascension REQDEC -7.093 float [deg] Tile Declination FIELDNUM 0 int Not used, always zero FA_VER 5.4.0 str Fiberassign code version FA_SURV main str Survey of origin of the targets ======== ========================= ===== ======================= Required Data Table Columns ~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. rst-class:: columns ===================== ======= ============== =================== Name Type Units Description ===================== ======= ============== =================== TARGETID int64 Unique target ID PETAL_LOC int16 Petal location [0-9] DEVICE_LOC int32 Device location on focal plane [0-523] LOCATION int32 Location on the focal plane PETAL_LOC*1000 + DEVICE_LOC FIBER int32 Fiber ID on the CCDs [0-4999] FIBERSTATUS int32 Fiber status mask; 0=good TARGET_RA float64 deg Target Right Ascension TARGET_DEC float64 deg Target Declination PMRA float32 mas/yr Proper motion in the RA direction (already including cosDEC term) PMDEC float32 mas/yr Proper motion in the DEC direction REF_EPOCH float32 yr Reference catalog reference epoch (eg, 2015.5 for Gaia DR2) LAMBDA_REF float32 Angstrom Wavelength at which targets should be centered on fibers FA_TARGET int64 Targeting bit internally used by fiberassign (linked with FA_TYPE) FA_TYPE binary Target type (science, standard, sky, safe, suppsky) OBJTYPE char[3] TGT, SKY, BAD, empty FIBERASSIGN_X float32 mm Expected CS5 X location on focal plane FIBERASSIGN_Y float32 mm Expected CS5 Y location on focal plane PRIORITY int32 Assignment priority; larger = higher priority SUBPRIORITY float64 Assignment subpriority [0-1] OBSCONDITIONS int32 Bit-coded of allowed observing conditions RELEASE int16 Imaging release number BRICKNAME char[8] Imaging Surveys brick name BRICKID int32 Imaging Surveys brick ID BRICK_OBJID int32 Imaging surveys OBJID on that brick MORPHTYPE char[4] Imaging surveys morphological type EBV float32 mag Galactic extinction E(B-V) reddening FLUX_G float32 nanomaggy Flux in g-band FLUX_R float32 nanomaggy Flux in r-band FLUX_Z float32 nanomaggy Flux in z-band FLUX_W1 float32 nanomaggy Flux in WISE W1-band FLUX_W2 float32 nanomaggy Flux in WISE W2-band FLUX_IVAR_G float32 nanomaggy^-2 Inverse variance of FLUX_G FLUX_IVAR_R float32 nanomaggy^-2 Inverse variance of FLUX_R FLUX_IVAR_Z float32 nanomaggy^-2 Inverse variance of FLUX_Z FLUX_IVAR_W1 float32 nanomaggy^-2 Inverse variance of FLUX_W1 FLUX_IVAR_W2 float32 nanomaggy^-2 Inverse variance of FLUX_W2 FIBERFLUX_G float32 nanomaggy g-band object model flux for 1 arcsec seeing and 1.5 arcsec diameter fiber FIBERFLUX_R float32 nanomaggy r-band object model flux for 1 arcsec seeing and 1.5 arcsec diameter fiber FIBERFLUX_Z float32 nanomaggy z-band object model flux for 1 arcsec seeing and 1.5 arcsec diameter fiber FIBERTOTFLUX_G float32 nanomaggy like FIBERFLUX_G but including all objects overlapping this location FIBERTOTFLUX_R float32 nanomaggy like FIBERFLUX_R but including all objects overlapping this location FIBERTOTFLUX_Z float32 nanomaggy like FIBERFLUX_Z but including all objects overlapping this location MASKBITS int16 Bitwise mask from the imaging indicating potential issue or blending SERSIC float32 Power-law index for the Sersic profile model SHAPE_R float32 arcsec Half-light radius of galaxy model for galaxy type SHAPE_E1 float32 Ellipticity component 1 of galaxy model for galaxy type SHAPE_E2 float32 Ellipticity component 2 of galaxy model for galaxy type REF_ID int64 Astrometric catalog reference ID (SOURCE_ID from Gaia and SGA; built from TYC1, TYC2, TYC3 for Tycho2) REF_CAT char[2] Reference catalog source for this star GAIA_PHOT_G_MEAN_MAG float32 mag Gaia G band mag GAIA_PHOT_BP_MEAN_MAG float32 mag Gaia BP mag GAIA_PHOT_RP_MEAN_MAG float32 mag Gaia RP mag PARALLAX float32 mas Reference catalog parallax PHOTSYS char[1] 'N' for the MzLS/BASS photometric system, 'S' for DECaLS, 'G' for Gaia, '' for stuck/broken fibers PRIORITY_INIT int64 Initial priority for target calculated across target selection bitmasks and OBSCONDITIONS NUMOBS_INIT int64 Initial number of observations for target calculated across target selection bitmasks and OBSCONDITIONS DESI_TARGET int64 Dark survey + calibration bitmask BGS_TARGET int64 Bright Galaxy Survey bitmask MWS_TARGET int64 Milky Way Survey bitmask SCND_TARGET int64 Secondary programs bitmask PLATE_RA float64 deg Right Ascension to be used by PlateMaker PLATE_DEC float64 deg Declination to be used by PlateMaker ===================== ======= ============== =================== HDU2 ---- EXTNAME = SKY_MONITOR Blank sky assignments for sky monitor positioners. Required Header Keywords ~~~~~~~~~~~~~~~~~~~~~~~~ .. collapse:: Required Header Keywords Table .. rst-class:: keywords ======== ========================= ===== ======================= KEY Example Value Type Comment ======== ========================= ===== ======================= NAXIS1 99 int width of table in bytes NAXIS2 20 int number of rows in table TILEID 4403 int Tile ID TILERA 170.239 float [deg] Tile Right Ascension TILEDEC -7.093 float [deg] Tile Declination FIELDROT 0.0210480650645507 float [deg] Field rotation FA_PLAN 2022-07-01T00:00:00.000 str [UTC] Plan field rotations for this date FA_HA -6.72 float [deg] Design Hour Angle FA_RUN 2022-01-03T17:00:31+00:00 str [UTC] Date of the loaded Focal Plane state FA_M_GFA 0.4 float [mm] Margin around GFA keep-out polygons FA_M_PET 0.4 float [mm] Margin around petal-boundary keep-out polygons FA_M_POS 0.05 float [mm] Margin around positioner keep-out polygons REQRA 170.239 float [deg] Tile Right Ascension REQDEC -7.093 float [deg] Tile Declination FIELDNUM 0 int Not used, always zero FA_VER 5.4.0 str Fiberassign code version FA_SURV main str Survey of origin of the targets ======== ========================= ===== ======================= Required Data Table Columns ~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. rst-class:: columns ============= ======= =========== =================== Name Type Units Description ============= ======= =========== =================== FIBER int32 Fiber ID on the CCDs [0-4999] LOCATION int32 Location on the focal plane PETAL_LOC*1000 + DEVICE_LOC TARGETID int64 Unique target ID BRICKID int32 Imaging Surveys brick ID BRICK_OBJID int32 Imaging surveys OBJID on that brick FA_TARGET int64 Targeting bit internally used by fiberassign (linked with FA_TYPE) FA_TYPE binary Target type (science, standard, sky, safe, suppsky) TARGET_RA float64 deg Target Right Ascension TARGET_DEC float64 deg Target Declination FIBERASSIGN_X float32 mm Expected CS5 X location on focal plane FIBERASSIGN_Y float32 mm Expected CS5 Y location on focal plane BRICKNAME char[8] Imaging Surveys brick name FIBERSTATUS int32 Fiber status mask; 0=good PETAL_LOC int16 Petal location [0-9] DEVICE_LOC int32 Device location on focal plane [0-523] PRIORITY int32 Assignment priority; larger = higher priority SUBPRIORITY float64 Assignment subpriority [0-1] FIBERFLUX_G float32 nanomaggy Flux in g-band FIBERFLUX_R float32 nanomaggy Flux in r-band FIBERFLUX_Z float32 nanomaggy Flux in z-band ============= ======= =========== =================== HDU3 ---- EXTNAME = GFA_TARGETS GFA stars to be used by the ETC / GUIDE / FOCUS Required Header Keywords ~~~~~~~~~~~~~~~~~~~~~~~~ .. collapse:: Required Header Keywords Table .. rst-class:: keywords ======== ========================= ===== ======================= KEY Example Value Type Comment ======== ========================= ===== ======================= NAXIS1 172 int width of table in bytes NAXIS2 988 int number of rows in table TILEID 4403 int Tile ID TILERA 170.239 float [deg] Tile Right Ascension TILEDEC -7.093 float [deg] Tile Declination FIELDROT 0.0210480650645507 float [deg] Field rotation FA_PLAN 2022-07-01T00:00:00.000 str [UTC] Plan field rotations for this date FA_HA -6.72 float [deg] Design Hour Angle FA_RUN 2022-01-03T17:00:31+00:00 str [UTC] Date of the loaded Focal Plane state FA_M_GFA 0.4 float [mm] Margin around GFA keep-out polygons FA_M_PET 0.4 float [mm] Margin around petal-boundary keep-out polygons FA_M_POS 0.05 float [mm] Margin around positioner keep-out polygons REQRA 170.239 float [deg] Tile Right Ascension REQDEC -7.093 float [deg] Tile Declination FIELDNUM 0 int Not used, always zero FA_VER 5.4.0 str Fiberassign code version FA_SURV main str Survey of origin of the targets ======== ========================= ===== ======================= Required Data Table Columns ~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. rst-class:: columns ================================= ======= ============== =================== Name Type Units Description ================================= ======= ============== =================== RELEASE int32 Imaging release number TARGETID int64 Unique target ID BRICKID int32 Imaging Surveys brick ID BRICK_OBJID int32 Imaging surveys OBJID on that brick TARGET_RA float64 deg Target Right Ascension TARGET_DEC float64 deg Target Declination TARGET_RA_IVAR float32 deg^-2 Inverse variance of TARGET_RA TARGET_DEC_IVAR float32 deg^-2 Inverse variance of TARGET_DEC MORPHTYPE char[4] Imaging surveys morphological type MASKBITS int16 Bitwise mask from the imaging indicating potential issue or blending FLUX_G float32 nanomaggy Flux in g-band FLUX_R float32 nanomaggy Flux in r-band FLUX_Z float32 nanomaggy Flux in z-band FLUX_IVAR_G float32 nanomaggy^-2 Inverse variance of FLUX_G FLUX_IVAR_R float32 nanomaggy^-2 Inverse variance of FLUX_R FLUX_IVAR_Z float32 nanomaggy^-2 Inverse variance of FLUX_Z REF_ID int64 Astrometric catalog reference ID (SOURCE_ID from Gaia and SGA; built from TYC1, TYC2, TYC3 for Tycho2) REF_CAT char[2] Reference catalog source for this star REF_EPOCH float32 yr Reference catalog reference epoch PARALLAX float32 mas Reference catalog parallax PARALLAX_IVAR float32 mas^-2 Inverse variance of PARALLAX PMRA float32 mas/yr Proper motion in the RA direction (already including cosDEC term) PMDEC float32 mas/yr Proper motion in the DEC direction PMRA_IVAR float32 yr^2/mas^2 Inverse variance of PMRA PMDEC_IVAR float32 yr^2/mas^2 Inverse variance of PMDEC GAIA_PHOT_G_MEAN_MAG float32 mag Gaia G band mag GAIA_PHOT_G_MEAN_FLUX_OVER_ERROR float32 Gaia G band signal-to-noise GAIA_PHOT_BP_MEAN_MAG float32 mag Gaia BP band mag GAIA_PHOT_BP_MEAN_FLUX_OVER_ERROR float32 Gaia BP signal-to-noise GAIA_PHOT_RP_MEAN_MAG float32 mag Gaia RP band mag GAIA_PHOT_RP_MEAN_FLUX_OVER_ERROR float32 Gaia RP signal-to-noise GAIA_ASTROMETRIC_EXCESS_NOISE float32 Gaia astrometric excess noise URAT_ID int64 URAT ID URAT_SEP float32 arcsec Distance separation to the URAT coordinates GAIA_PHOT_G_N_OBS int32 Gaia G band number of observations HPXPIXEL int64 HEALPixel containing GFA target GFA_LOC int16 Covered GFA identifier GUIDE_FLAG int16 GUIDING bitmask FOCUS_FLAG int16 FOCUS bitmask ETC_FLAG int16 ETC bitmask ================================= ======= ============== =================== HDU4 ---- EXTNAME = TARGETS Unique list of targets reachable by a positioner. Required Header Keywords ~~~~~~~~~~~~~~~~~~~~~~~~ .. collapse:: Required Header Keywords Table .. rst-class:: keywords ======== ========================= ===== ======================= KEY Example Value Type Comment ======== ========================= ===== ======================= NAXIS1 81 int width of table in bytes NAXIS2 152687 int number of rows in table TILEID 4403 int Tile ID TILERA 170.239 float [deg] Tile Right Ascension TILEDEC -7.093 float [deg] Tile Declination FIELDROT 0.0210480650645507 float [deg] Field rotation FA_PLAN 2022-07-01T00:00:00.000 str [UTC] Plan field rotations for this date FA_HA -6.72 float [deg] Design Hour Angle FA_RUN 2022-01-03T17:00:31+00:00 str [UTC] Date of the loaded Focal Plane state FA_M_GFA 0.4 float [mm] Margin around GFA keep-out polygons FA_M_PET 0.4 float [mm] Margin around petal-boundary keep-out polygons FA_M_POS 0.05 float [mm] Margin around positioner keep-out polygons REQRA 170.239 float [deg] Tile Right Ascension REQDEC -7.093 float [deg] Tile Declination FIELDNUM 0 int Not used, always zero FA_VER 5.4.0 str Fiberassign code version FA_SURV main str Survey of origin of the targets ======== ========================= ===== ======================= Required Data Table Columns ~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. rst-class:: columns ============= ======= ===== =================== Name Type Units Description ============= ======= ===== =================== TARGETID int64 Unique target ID RA float64 deg Target Right Ascension DEC float64 deg Target Declination FA_TARGET int64 Targeting bit internally used by fiberassign (linked with FA_TYPE) FA_TYPE binary Target type (science, standard, sky, safe, suppsky) PRIORITY int32 Assignment priority; larger = higher priority SUBPRIORITY float64 Assignment subpriority [0-1] OBSCONDITIONS int32 Bit-coded of allowed observing conditions DESI_TARGET int64 Dark survey + calibration bitmask BGS_TARGET int64 Bright Galaxy Survey bitmask MWS_TARGET int64 Milky Way Survey bitmask SCND_TARGET int64 Secondary programs bitmask ============= ======= ===== =================== HDU5 ---- EXTNAME = POTENTIAL_ASSIGNMENTS A list of targets that could have been assigned to each fiber. Required Header Keywords ~~~~~~~~~~~~~~~~~~~~~~~~ .. collapse:: Required Header Keywords Table .. rst-class:: keywords ======== ========================= ===== ======================= KEY Example Value Type Comment ======== ========================= ===== ======================= NAXIS1 16 int width of table in bytes NAXIS2 169775 int number of rows in table TILEID 4403 int Tile ID TILERA 170.239 float [deg] Tile Right Ascension TILEDEC -7.093 float [deg] Tile Declination FIELDROT 0.0210480650645507 float [deg] Field rotation FA_PLAN 2022-07-01T00:00:00.000 str [UTC] Plan field rotations for this date FA_HA -6.72 float [deg] Design Hour Angle FA_RUN 2022-01-03T17:00:31+00:00 str [UTC] Date of the loaded Focal Plane state FA_M_GFA 0.4 float [mm] Margin around GFA keep-out polygons FA_M_PET 0.4 float [mm] Margin around petal-boundary keep-out polygons FA_M_POS 0.05 float [mm] Margin around positioner keep-out polygons REQRA 170.239 float [deg] Tile Right Ascension REQDEC -7.093 float [deg] Tile Declination FIELDNUM 0 int Not used, always zero FA_VER 5.4.0 str Fiberassign code version FA_SURV main str Survey of origin of the targets ======== ========================= ===== ======================= Required Data Table Columns ~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. rst-class:: columns ======== ===== ===== =================== Name Type Units Description ======== ===== ===== =================== TARGETID int64 Unique target ID FIBER int32 Fiber ID on the CCDs [0-4999] LOCATION int32 Location on the focal plane PETAL_LOC*1000 + DEVICE_LOC ======== ===== ===== =================== Notes and Examples ================== For the SURVEY=cmx m33 tile (TILEID=80615) tile and all the SURVEY=sv1 tiles (except TILEID=80971-80976, the dc3r2 ones), proper-motion correction was applied at the :doc:`fiberassign ` design step; thus the following columns can have different values than in the :doc:`desitarget products `: ``TARGET_RA``, ``TARGET_DEC``, ``REF_EPOCH``, ``PLATE_RA``, ``PLATE_DEC``, and ``PLATE_REF_EPOCH``. * HDU0: early tiles may have some missing keywords from the listed ones. * HDU1: this table defines the *requested* fiber assignments; see :doc:`fibermap-EXPID <../../../../../DESI_SPECTRO_DATA/NIGHT/EXPID/fibermap-EXPID>` for the actual observed assignments. * HDU1: ``LAMBDA_REF`` : 5400 so far, not used for fiber positioning. * HDU1, HDU4, HDU5: files built from CMX, SV1, SV2, or SV3 targets will have a slightly different column content for the targetings bit columns (e.g., ``CMX_TARGET``, ``SV1_DESI_TARGET``). * HDU2: ``BRICKID``, ``BRICK_OBJID``, ``FA_TARGET``, ``BRICKNAME``, ``PRIORITY``, ``SUBPRIORITY``, ``FIBERFLUX_G``, ``FIBERFLUX_R``, ``FIBERFLUX_Z`` mostly are a zero value (and an empty string for ``BRICKNAME``). * HDU3: for objects that do not have a match in URAT, the ``URAT_ID`` and ``URAT_SEP`` columns are -1. * HDU5: the same target can appear more than once if it is reachable by more than one fiber.