General description: The spPlate files contain the combined spectra for all exposures of a given plate. There are typically three 900s exposures which may have been taken in a single night, or over multiple nights. This page is an updated summary of the SDSS2 spPlate data model.
Naming convention: spPlate-pppp-mmmmm.fits, where pppp is a 4-digit plate number, and mmmmm is a 5-digit MJD.
Approximate size: 60 Mbytes.
File type: FITS
Read by products: spreduce1d, sspp
Written by products: spcombine
| HDU0 | NPIX x 640 float image | Flux in units of 10^-17^ erg/s/cm^2^/Ang |
| HDU1 | NPIX x 640 float image | Inverse variance (1/sigma^2^) for HDU 0 |
| HDU2 | NPIX x 640 32-bit int image | AND mask |
| HDU3 | NPIX x 640 32-bit int image | OR mask |
| HDU4 | NPIX x 640 float image | Wavelength dispersion in pixels |
| HDU5 fields | binary table | Plug-map structure from plPlugMapM file |
| HDU6 | NPIX x 640 float image | Average sky flux in units of 10^-17^ erg/s/cm^2^/Ang |
Note: Additional HDUs may be present for engineering purposes, but are not supported and are subject to change. Users should refrain from using HDUs not listed here.
SIMPLE FIT STANDARD BITPIX PIXEL NAXIS NUMBER OF AXES NAXIS1 WIDTH (TOTAL!) NAXIS2 HEIGHT (TOTAL!) EXTEND TAI 1st row - Number of seconds since Nov 17 1858 RA 1st row - Right ascension of telescope boresigh DEC 1st row - Declination of telescope boresight (d EQUINOX RADECSYS AZ 1st row - Azimuth (encoder) of tele (0=N?) (de ALT 1st row - Altitude (encoder) of tele (de AIRMASS FOCUS 1st row - Focus piston (microns?) DATE-OBS 1st row - TAI date TAIHMS 1st row - TAI time (HH:MM:SS.SS) (TAI-UT = appr TIMESYS TAI, not UTC TAI-BEG Exposure Start Time TAI-END Exposure End Time MJD MJD of observation MJDLIST VERSION version of IOP CAMVER Camera code version OBSERVER OBSCOMM TELESCOP Sloan Digital Sky Survey NEXP Number of exposures in this file BESTEXP EXPID01 ID string for exposure 1 EXPID02 ID string for exposure 2 EXPID03 ID string for exposure 3 EXPID04 ID string for exposure 4 EXPID05 ID string for exposure 5 EXPID06 ID string for exposure 6 EXPID07 ID string for exposure 7 EXPID08 ID string for exposure 8 EXPID09 ID string for exposure 9 EXPID10 ID string for exposure 10 EXPID11 ID string for exposure 11 EXPID12 ID string for exposure 12 NEXP_B1 b1 camera number of exposures NEXP_B2 b2 camera number of exposures NEXP_R1 r1 camera number of exposures NEXP_R2 r2 camera number of exposures EXPT_B1 b1 camera exposure time (seconds) EXPT_B2 b2 camera exposure time (seconds) EXPT_R1 r1 camera exposure time (seconds) EXPT_R2 r2 camera exposure time (seconds) EXPTIME Minimum of exposure times for all cameras SPCOADD SPCOADD finished FLAVOR Flavor of this sequence (e.g., dome f QUALITY image quality RADEG Right Ascension. (degrees) DECDEG Declination. (degrees) PLATEID Plate Id TILEID Tile Id CARTID Cartridge used in this plugging REDDEN Median reddening vector for plate MAPID Map Id NAME Name of the currently loaded plugging pppp-mmmmm-dd format NGUIDE Number of guider frames during exposure SEEING20 20% seeing during exposure (arcsec) SEEING50 50% seeing during exposure (arcsec) SEEING80 80% seeing during exposure (arcsec) RMSOFF20 20% RMS offset of guide fibers (arcsec) RMSOFF50 50% RMS offset of guide fibers (arcsec) RMSOFF80 80% RMS offset of guide fibers (arcsec) COLBIN Binning factor perpendicular to the c ROWBIN Binning factor perpendicular to the r PROGRAM Identifying name for CCD program SECFOCUS Secondary Mirror Position as reported GUIDEIMG Last archived guider image WTIME weatherData(timeStamp) AIRTEMP weatherData(airtemp) DEWPOINT weatherData(dewpoint) DEWDEP weatherData(dewpointDep) DUSTA weatherData(dusta) DUSTB weatherData(dustb) DUSTC weatherData(dustc) DUSTD weatherData(dustd) GUSTD weatherData(gustd) GUSTS weatherData(gusts) HUMIDITY weatherData(humidity) HUMIDOUT weatherData(humidout) PRESSURE weatherData(pressure) WINDD weatherData(windd) WINDS weatherData(winds) TEMP01 CCD 01 Temperature TEMP02 CCD 02 Temperature TEMP03 CCD 03 Temperature TEMP04 CCD 04 Temperature AUTHOR VERSIDL Version of IDL VERSUTIL Version of idlutils VERSREAD Version of idlspec2d for pre-processing raw dat VERS2D Version of idlspec2d for 2D reduction VERSCOMB Version of idlspec2d for combining multiple spe VERSLOG Version of SPECLOG product VERSFLAT Version of SPECFLAT product OPBC OPCONFIG OPECALIB XSIGMA XSIGMIN XSIGMAX WSIGMA WSIGMIN WSIGMAX PLUGFILE LAMPLIST SKYLIST HELIO_RV Heliocentric correction (added to velocities) VACUUM Wavelengths are in vacuum SFLATTEN Superflat has been applied PSFSKY Order of PSF skysubtraction SKYCHI2 Mean chi^2 of sky-subtraction SCHI2MIN SCHI2MAX PREJECT Profile area rejection threshold SPEC1_G (S/N)^2 for spec 1 at mag 20.20 SPEC1_R (S/N)^2 for spec 1 at mag 20.25 SPEC1_I (S/N)^2 for spec 1 at mag 19.90 SPEC2_G (S/N)^2 for spec 2 at mag 20.20 SPEC2_R (S/N)^2 for spec 2 at mag 20.25 SPEC2_I (S/N)^2 for spec 2 at mag 19.90 NSTD Number of (good) std stars GOFFSTD Spectrophoto offset for std stars in G-band GRMSSTD Spectrophoto RMS for std stars in G-band ROFFSTD Spectrophoto offset for std stars in R-band RRMSSTD Spectrophoto RMS for std stars in R-band IOFFSTD Spectrophoto offset for std stars in I-band IRMSSTD Spectrophoto RMS for std stars in I-band GROFFSTD Spectrophoto offset for std stars in (GR) GRRMSSTD Spectrophoto RMS for std stars in (GR) RIOFFSTD Spectrophoto offset for std stars in (RI) RIRMSSTD Spectrophoto RMS for std stars in (RI) LOWREJ Extraction: low rejection HIGHREJ Extraction: high rejection SCATPOLY Extraction: Order of scattered light polynomial PROFTYPE Extraction profile: 1=Gaussian NFITPOLY Extraction: Number of parameters in each profil XCHI2 Extraction: Mean chi^2 XCHI2MIN XCHI2MAX SHIFTGUE SHIFT Angstroms, at 4000AA SHIFTERR NWORDER Linear-log10 coefficients COEFF0 Central wavelength (log10) of first pixel COEFF1 Log10 dispersion per pixel UNAME FBADPIX Fraction of bad pixels FBADPIX1 Fraction of bad pixels on spectro-1 FBADPIX2 Fraction of bad pixels on spectro-2 WAT0_001 WAT1_001 CRVAL1 Central wavelength (log10) of first pixel CD1_1 Log10 dispersion per pixel CRPIX1 Starting pixel (1-indexed) CTYPE1 DC-FLAG Log-linear flag BUNIT END
XTENSION IMAGE extension BITPIX Number of bits per data pixel NAXIS Number of data axes NAXIS1 NAXIS2 PCOUNT No Group Parameters GCOUNT One Data Group WAT0_001 WAT1_001 CRVAL1 Central wavelength (log10) of first pixel CD1_1 Log10 dispersion per pixel CRPIX1 Starting pixel (1-indexed) CTYPE1 DC-FLAG Log-linear flag BUNIT END
XTENSION IMAGE extension BITPIX Number of bits per data pixel NAXIS Number of data axes NAXIS1 NAXIS2 PCOUNT No Group Parameters GCOUNT One Data Group WAT0_001 WAT1_001 CRVAL1 Central wavelength (log10) of first pixel CD1_1 Log10 dispersion per pixel CRPIX1 Starting pixel (1-indexed) CTYPE1 DC-FLAG Log-linear flag END
XTENSION IMAGE extension BITPIX Number of bits per data pixel NAXIS Number of data axes NAXIS1 NAXIS2 PCOUNT No Group Parameters GCOUNT One Data Group WAT0_001 WAT1_001 CRVAL1 Central wavelength (log10) of first pixel CD1_1 Log10 dispersion per pixel CRPIX1 Starting pixel (1-indexed) CTYPE1 DC-FLAG Log-linear flag END
XTENSION IMAGE extension BITPIX Number of bits per data pixel NAXIS Number of data axes NAXIS1 NAXIS2 PCOUNT No Group Parameters GCOUNT One Data Group WAT0_001 WAT1_001 CRVAL1 Central wavelength (log10) of first pixel CD1_1 Log10 dispersion per pixel CRPIX1 Starting pixel (1-indexed) CTYPE1 DC-FLAG Log-linear flag BUNIT END
XTENSION Binary table written by MWRFITS v1.4a BITPIX Required value NAXIS Required value NAXIS1 Number of bytes per row NAXIS2 Number of rows PCOUNT Normally 0 (no varying arrays) GCOUNT Required value TFIELDS Number of columns in table END
OBJID LONG Array(5) HOLETYPE STRING SS RA DOUBLE D.DD in decimal degrees DEC DOUBLE D.DD in decimal degrees MAG FLOAT Array(5) STARL FLOAT F.FF EXPL FLOAT F.FF DEVAUCL FLOAT F.FF OBJTYPE STRING SS XFOCAL DOUBLE D.DD YFOCAL DOUBLE D.DD SPECTROGRAPHID LONG LL FIBERID LONG LL THROUGHPUT LONG LL PRIMTARGET LONG LL SECTARGET LONG LL OFFSETID LONG LL SCI_EXPTIME FLOAT F.FF CALIBFLUX FLOAT Array(5) CALIBFLUX_IVAR FLOAT Array(5) SFD_EBV FLOAT F.FF
XTENSION Image Extension created by MWRFITS v1.4a BITPIX NAXIS NAXIS1 NAXIS2 PCOUNT GCOUNT END