Data model: photoField

General description: The photoField files contain the full, calibrated outputs of the SDSS imager photometric pipeline regarding the properties of each field in a camera dewar. They are parallel with the CAS field and fieldProfile tables.

Naming convention: photoField-RUN6-CAMCOL.fits

Approximate size: 2 Mbytes.

File type: FITS

Read by products: sas

Written by products: photoop

Required header keywords: (none)

Required column names: (should be listed for Yanny and FITS)

• fieldID (string): Field identifier composed of [run, camcol, field, rerun, skyversion].
• skyVersion (int8): Layer of catalog (currently only one layer, 0)
• run (int16): Run number
• rerun (int16): Rerun number
• camcol (int8): Camera column
• field (int16): Field number
• nObjects (int16): Number of (non-BRIGHT) objects in the field
• nChild (int16): Number of "child" objects in the field
• ngals (int16): Number of objects classified as "galaxy"
• nStars (int16): Number of objects classified as "star"
• nCR[5] (int16): Number of cosmics
• nBrightObj[5] (int16): Number of bright objects
• nFaintObj[5] (int16): Number of faint objects
• quality (int32): Quality of field
• mjd[5] (float64): MJD(TAI) when row 0 of u-band field was read
• a[5] (float32): a term in astrometry
• b[5] (float32): b term in astrometry
• c[5] (float32): c term in astrometry
• d[5] (float32): d term in astrometry
• e[5] (float32): e term in astrometry
• f[5] (float32): f term in astrometry
• dRow0[5] (float32): Zero-order row distortion coefficient
• dRow1[5] (float32): First-order row distortion coefficient
• dRow2[5] (float32): Second-order row distortion coefficient
• dRow3[5] (float32): Third-order row distortion coefficient
• dCol0[5] (float32): Zero-order column distortion coefficient
• dCol1[5] (float32): First-order column distortion coefficient
• dCol2[5] (float32): Second-order column distortion coefficient
• dCol3[5] (float32): Third-order column distortion coefficient
• csRow[5] (float32): Slope in row DCR correction for blue objects
• csCol[5] (float32): Slope in column DCR correction for blue objects
• ccRow[5] (float32): Constant row DCR correction for blue objects
• ccCol[5] (float32): Constant column DCR correction for blue objects
• riCut[5] (float32): r-i cutoff between blue and red objects
• airmass[5] (float32): Airmass for star at frame center (midway through u-band exposure) (mag)
• muErr[5] (float32): Error in mu in astrometric calibration (arcsec)
• nuErr[5] (float32): Error in nu in astrometric calibration (arcsec)
• raMin (float64): Minimum RA of field (deg)
• raMax (float64): Maximum RA of field (deg)
• decMin (float64): Minimum Dec of field (deg)
• decMax (float64): Maximum Dec of field (deg)
• pixScale[5] (float64): Mean size of pixel (r-band) (arcsec)
• primaryArea (float64): Area covered by primary part of field (deg)
• rowOffset[5] (float32): Offset to add to transformed row coordinates (pix)
• colOffset[5] (float32): Offset to add to transformed row coordinates (pix)
• saturation_level[5] (int32): Saturation level (counts)
• neff_psf[5] (float32): Effective area of PSF (pix)
• sky_psp[5] (float32): Sky estimate from PSP (nmgy)
• sky_frames[5] (float32): Frames sky value (nmgy)
• sky_frames_sub[5] (float32): Frames sky value after object subtraction (nmgy)
• sigPix[5] (float32): Sigma of pixel values frame (clipped) (nmgy)
• dev_ap_correction[5] (float32): deV aperture correction
• dev_ap_correctionerr[5] (float32): Error in deV aperture correction
• exp_ap_correction[5] (float32): exponential aperture correction
• exp_ap_correctionerr[5] (float32): Error in exponential aperture correction
• dev_model_ap_correction[5] (float32): model aperture correction, for deV case
• dev_model_ap_correctionerr[5] (float32): Error in model aperture correction, for deV case
• exp_model_ap_correction[5] (float32): model aperture correction, for exponential case
• exp_model_ap_correctionerr[5] (float32): Error in model aperture correction, for exponential case
• median_fibercolor (float32): Median fiber magnitude of objects
• median_psfcolor (float32): Median PSF magnitude of objects
• q[5] (float32): Means Stokes Q parameter frame
• u[5] (float32): Means Stokes U parameter frame
• sky[5] (float32): PSP estimate of sky (nmgy)
• skySig[5] (float32): Fractional Sigma of Sky Value Distribution, expressed as magnitude. Sky noise = skySig * sky * ln(10)/2.5 (mag)
• skyErr[5] (float32): Error in PSP estimate of sky (nmgy)
• skySlope[5] (float32): Rate of change in sky value along columns (nmgy)
• lbias[5] (float32): Left-hand amplifier bias level XXX make sure to apply DSCALE, counts or ADU? (ADUs)
• rbias[5] (float32): Right-hand amplifier bias level (ADUs)
• psf_nstar[5] (int32): Number of stars used in PSF measurement
• psf_ap_correctionerr[5] (float32): Photometric uncertainty due to imperfect PSF model (mag)
• psf_sigma1[5] (float32): Inner gaussian sigma for composite fit (arcsec)
• psf_sigma2[5] (float32): Outer gaussian sigma for composite fit (arcsec)
• psf_b[5] (float32): Ratio of inner to outer components at origin (composite fit)
• psf_p0[5] (float32): Value of power law at origin in composite fit XXX
• psf_beta[5] (float32): Slope of power law in composite fit
• psf_sigmap[5] (float32): Width of power law in composite fit
• psf_width[5] (float32): Effective PSF width from 2-Gaussian fit (arcsec)
• psf_psfcounts[5] (float32): Flux via fit to PSF XXX (counts)
• psf_sigma1_2g[5] (float32): Sigma of inner gaussian in 2-Gaussian fit (arcsec)
• psf_sigma2_2g[5] (float32): Sigma of outer gaussian in 2-Gaussian fit (arcsec)
• psf_b_2g[5] (float32): Ratio of inner to outer components at origin (2-Gaussian fit)
• psfCounts[5] (float32): PSF counts XXX (counts)
• gain[5] (float32): Gain averaged over amplifiers (electrons)
• dark_variance[5] (float32): Dark variance
• score (float32): Quality score of field (0-1)
• aterm[5] (float32): nanomaggies per count due to instrument (nmgy)
• kterm[5] (float32): atmospheric k-term at reference time in calibration
• kdot[5] (float32): linear time variation of atmospheric k-term (1)
• ref_tai[5] (float64): reference TAI used for k-term (second)
• tai[5] (float64): TAI used for k-term (second)
• psp_status (int16): Maximum value of status over all 5 filters
• photo_status (int32): Frames processing status bitmask (-1: UNKNOWN, 0: OK, 1: ABORTED; 2:MISSING, 3:TOO_LONG); from fpFieldStat file)
• image_status (int32): image status bitmask
• calib_status (int32): calibration status bitmask
• nstar_offset (int32): number of stars used for fieldOffset determination
• field_offset (int32): offset of field from initial calibration (final minus initial magnitudes) (mag)
• nMgyPerCount (float32): nanomaggies per count (nmgy)
• nMgyPerCount_Ivar (float32): Inverse variance of nanomaggies per count ()
• sun_angle (float32): altitude of Sun at time of observation (deg)
• ifield (int32): field id used by resolve pipeline
• mu_start (float64): start of field in stripe coords (parallel to scan direction)
• mu_end (float64): end of field in stripe coords (parallel to scan direction)
• nu_start (float64): start of field in stripe coords (perpendicular to scan direction)
• nu_end (float64): end of field in stripe coords (perpendicular to scan direction)
• ifindx (int32): first entry for this field in the window_findx.fits file matching the fields to balkans
• nbalkans (int32): number of balkans contained in this field (and corresponding number of entries in window_findx.fits

Example file: photoField-004623-1.fits