Field


All the measured parameters of a photometric field are stored in this object.


Aliases: sxField, field

Data Members of Field:
Member Name/AliasesDatatypeDescription
fieldID;
id,;
field_ID 		int64 Unique field identifier: Bitmask consisting of run,rerun,camcol, fieldnumber
field;
fieldNumber 		int32 Field number
nObjects;
nobj 		int32 Number of objects in the field
nDetectedObjects;
ndetected 		int32 Number of objects actually detected
nChild;
nchild 		int32 Number of 'child' objects
nGalaxy;
nGals;
ngals;
ngalaxy;
n_gals 		int32 Number of objects classified as 'galaxy'
nStars;
nstars;
n_stars 		int32 Number of objects classified as 'star'
numStars;
numstars;
num_stars 		int32[5] Number of stars found in each band
nCR;
n_CR 		int32[5] Number of cosmic rays in each band
nBrightObj;
n_bright_obj 		int32[5] Number of bright objects in each band
nFaintObj;
n_faint_obj 		int32[5] Number of faint (nonbright) objects in each band
quality int32 The quality of data in the field, in terms of its acceptance for the survey: BAD, ACCEPTABLE, GOOD, MISSING, HOLE. These have the following meanings: 
  AR_DQ_BAD        = 1,  * Not acceptable for the survey
  AR_DQ_ACCEPTABLE = 2,  * Acceptable for the survey, but we'd better data
  AR_DQ_GOOD       = 3,  * Fully acceptable --- no desire for better data
  AR_DQ_MISSING    = 4,  * No objects in this field, because data is missing,
                         * but we accept the field into the survey as a hole
                         * in the survey
  AR_DQ_HOLE       = 5,  * Data in this field is not acceptable, but we will
                         * accept the field into the survey as a hole in the
                         * survey, meaning none of the objects in the field
                         * are part of the survey
mjd;
MJD 		float64[5] MJD(TAI) when row 0 was read.
a float64[5] Astrometric transformation constants. mu, nu are defined as: 
  r'-i' < riCut
      rowm = row + dRow0 + dRow1*col + dRow2*(col^2) + dRow3*(col^3) + csRow*c
      colm = col + dCol0 + dCol1*col + dCol2*(col^2) + dCol3*(col^3) + csCol*c

  r'-i' >= riCut
      rowm = row + dRow0 + dRow1*col + dRow2*(col^2) + dRow3*(col^3) + ccRow
      colm = col + dCol0 + dCol1*col + dCol2*(col^2) + dCol3*(col^3) + ccCol

  mu = a + b * rowm + c * colm
  nu = d + e * rowm + f * colm
b float64[5]
c float64[5]
d float64[5]
e float64[5]
f float64[5]
dRow0;
d_row0 		float64[5] Zero-order row distortion coefficient.
dRow1;
d_row1 		float64[5] First-order row distortion coefficient.
dRow2;
d_row2 		float64[5] Second-order row distortion coefficient.
dRow3;
d_row3 		float64[5] Third-order row distortion coefficient.
dCol0;
d_col0 		float64[5] Zero-order column distortion coefficient.
dCol1;
d_col1 		float64[5] First-order column distortion coefficient.
dCol2;
d_col2 		float64[5] Second-order column distortion coefficient.
dCol3;
d_col3 		float64[5] Third-order column distortion coefficient.
csRow;
cs_row 		float64[5] Slope in row DCR correction for blue objects.
csCol;
cs_col 		float64[5] Slope in column DCR correction for blue objects
ccRow;
cc_row 		float64[5] Constant row DCR correction for red objects.
ccCol;
cc_col 		float64[5] Constant column DCR correction for red objects.
riCut;
ri_cut 		float64[5] r'-i' cutoff between blue and red objects.
airmass;
air_mass;
airMass 		float64[5] Airmass for star at frame center (mid exposure)
raMin;
ra_min 		float64 Minima/maxima of this field in ra/dec
raMax;
ra_max 		float64
decMin;
dec_min 		float64
decMax;
dec_max 		float64
scanlineArea;
scanLineArea;
scanline_area 		float32 Area of scanline covered by the field (deg^2)
stripeArea;
stripe_area 		float32 Area of stripe covered by the field (deg^2)
seqID;
seqId 		int32 Sequence id overlapping this field (-1=none)
aa float32[5] Zero-point.
aaErr;
aa_err 		float32[5] Zero-point error
bb float32[5] Color term.
bbErr;
bb_err 		float32[5] Color Term Error
cc float32[5] Color x extinction term.
ccErr;
cc_err 		float32[5] Color x extinction term. (error)
kk float32[5] Extinction coefficient.
kkErr;
kk_err 		float32[5] Extinction coefficient. (error)
framesStatus;
frames_status 		int32 Info from the fpFieldStat file : Frames Processing Status
rowOffset;
row_offset 		float32[5] Offset to add to transformed row coordinates.
colOffset;
col_offset 		float32[5] Offset to add to transformed column coordinates.
saturationLevel;
saturation_level 		int32[5] Saturation level
nEffPsf;
nEffPSF;
neff_psf 		float32[5] Effective area of the point spread function. (pixels)
skyPsp;
sky_psp 		float32[5] Sky from the point spread function. (luptitudes/arcsec^2)
skyFrames;
sky_frames 		float32[5] Global sky value in the corrected frame. (luptitudes/arcsec^2)
skyFramesSub;
sky_frames_sub 		float32[5] Global sky value after object subtraction. (luptitudes/arcsec^2)
sigPix;
sky_pix 		float32[5] Clipped sigma of pixel values in corrected frame (luptitudes/arcsec^2)
deVApCorrection;
deV_ap_correction 		float32[5] deV AP correction
deVApCorrectionErr;
deV_ap_correctionErr 		float32[5] deV AP correction error
expApCorrection;
exp_ap_correction 		float32[5] exp AP correction
expApCorrectionErr;
exp_ap_correctionErr 		float32[5] exp AP correction error
deVModelApCorrection;
deV_model_ap_correction 		float32[5] deV model AP correction
deVModelApCorrectionErr;
deV_model_ap_correctionErr 		float32[5] deV model AP correction error
expModelApCorrection;
exp_model_ap_correction 		float32[5] Exp model AP correction
expModelApCorrectionErr;
exp_model_ap_correctionErr 		float32[5] Exp model AP correction error
medianFiberColor;
median_fiberColor;
median_fiber_color 		float32[5] Median fiber colors of objects
medianPsfColor;
median_psfColor;
median_psf_color;
medianPSFColor 		float32[5] Median PSF colors of objects
q;
Q 		float32[5] Mean Stokes Q parameter on the frame?
u;
U 		float32[5] Mean Stokes U parameter on the frame?
pspStatus;
psp_status 		int16 The maximum value of "status" over all 5 filters.
culled int32 This attribute is a bit mask, with the exact same values as the primTarget bit mask. If a bit in the mask is set, it indicates that targets of that type were culled from that field, and therefore that field is excluded from that particular science sample. A given field may have a different value for "culled" in the drilling versus the current version of the sky (just as it can have a different value for "quality").
badMask int32 The four unsigned 32-bit integer bit masks "badMask", "acceptableMask", "goodMask", and "holeMask" indicate which quality categories were of the specified quality for each field. The bits are enumerated in the following way: 
  AR_FQ_SEEING           = 0x1,
  AR_FQ_TRACKING         = 0x2,
  AR_FQ_PSF              = 0x4,
  AR_FQ_PHOTOMETRY       = 0x8,
  AR_FQ_PHOTO_DROPOUT    = 0x10,
  AR_FQ_ODD_EVEN_DROPOUT = 0x20,
  AR_FQ_SKY_U            = 0x40,
  AR_FQ_SKY_G            = 0x80,
  AR_FQ_SKY_R            = 0x100,
  AR_FQ_SKY_I            = 0x200,
  AR_FQ_SKY_Z            = 0x400,
  AR_FQ_AMP_U0           = 0x800,
  AR_FQ_AMP_U1           = 0x1000,
  AR_FQ_AMP_G0           = 0x2000,
  AR_FQ_AMP_G1           = 0x4000,
  AR_FQ_AMP_R0           = 0x8000,
  AR_FQ_AMP_R1           = 0x10000,
  AR_FQ_AMP_I0           = 0x20000,
  AR_FQ_AMP_I1           = 0x40000,
  AR_FQ_AMP_Z0           = 0x80000,
  AR_FQ_AMP_Z1           = 0x100000,
  AR_FQ_MANUAL           = 0x200000
acceptableMask int32 See description of badMask
goodMask int32 See description of badMask
holeMask int32 See description of badMask
status int32[5] The status fields record the status of the PSF fit for that field in that filter, and can take the following meanings: 
  AR_PSF_STATUS_UNKNOWN = -1,    * ??? 
  AR_PSF_STATUS_OK      =  0,    * PSF fitted by 2nd order parabolas
  AR_PSF_STATUS_PSF22   =  1,    * PSF fitted by linear functions
  AR_PSF_STATUS_PSF11   =  2,    * PSF fitted by a constant
  AR_PSF_STATUS_NOPSF   =  3,    * PSF fit from previous frame used
  AR_PSF_STATUS_ABORTED =  4,    * ???
  AR_PSF_STATUS_MISSING =  5     * ???
sky float32[5] Average sky in frame (luptitudes/arcsec^2)
skySig;
sky_sig 		float32[5] Sigma of sky value distribution (luptitudes/arcsec^2)
skyErr;
sky_err 		float32[5] The error in the average sky in frame. (luptitudes/arcsec^2)
skySlope;
sky_slope 		float32[5] Slope in sky value along columns (luptitudes/arcsec^2/field)
lbias;
lBias;
l_bias 		float32[5] Left-hand bias level (ADUs x DSCALE)
rbias;
rBias;
r_bias 		float32[5] Right-hand bias level (ADUs x DSCALE)
psfNStar;
psf_nstar 		int32[5] Number of stars used in PSF measurement.
psfApCorrectionErr;
psf_ap_correctionErr 		float32[5] Photometric error due to imperfect PSF model (mags)
psfSigma1;
psf_sigma1 		float32[5] Inner gaussian sigma for the composite fit (arcsecs)
psfSigma2;
psf_sigma2 		float32[5] Outer gaussian sigma for the composite fit (arcsecs)
psfB;
psf_b 		float32[5] Ratio of the inner PSF to the outer PSF at the origin.
psfP0;
psf_p0 		float32[5] The value of the power law at the origin.
psfBeta;
psf_beta 		float32[5] Slope of power law
psfSigmaP;
psf_sigmap 		float32[5] Width parameter for power law
psfWidth;
psf_width 		float32[5] Effective PSF width, based on 2-Gaussian fit (arcsecs)
psfPsfCounts;
psf_psfCounts 		float32[5] Flux via fit to PSF (counts)
psf2GSigma1;
psf_sigma1_2G 		float32[5] PSF inner sigma 2G
psf2GSigma2;
psf_sigma2_2G 		float32[5] PSF outer sigma 2G
psf2GB;
psf_b_2G 		float32[5] PSF sigma ratio 2G
psfCounts;
psf_counts 		float32[5] PSF counts
gain float32[5] Gain averaged over amplifiers (electrons/DN)
darkVariance;
dark_variance 		float32[5] Dark variance
nProf;
prof_nprof;
n_prof 		int32[5] Number of profile bins
profMeanU;
prof_mean_u 		float32[] Mean profile u-band
profMeanG;
prof_mean_g 		float32[] Mean profile g-band
profMeanR;
prof_mean_r 		float32[] Mean profile r-band
profMeanI;
prof_mean_i 		float32[] Mean profile i-band
profMeanZ;
prof_mean_z 		float32[] Mean profile z-band
profMedU;
prof_med_u 		float32[] Median profile u-band
profMedG;
prof_med_g 		float32[] Median profile g-band
profMedR;
prof_med_r 		float32[] Median profile r-band
profMedI;
prof_med_i 		float32[] Median profile i-band
profMedZ;
prof_med_z 		float32[] Median profile z-band
profSigU;
prof_sig_u 		float32[] Profile sigma u-band
profSigG;
prof_sig_g 		float32[] Profile sigma g-band
profSigR;
prof_sig_r 		float32[] Profile sigma r-band
profSigI;
prof_sig_i 		float32[] Profile sigma i-band
profSigZ;
prof_sig_z 		float32[] Profile sigma z-band
photoobj;
PhotoObj;
pobj;
PhotoObj;
obj 		ManyAssoc(PhotoObj) To-Many link to the photometric objects in this field
segment;
Segment 		OneAssoc(Segment) To-One link to the segment this field is in

© Copyright 2000 Peter Z. Kunszt Alex S. Szalay , Ani R. Thakar
and The SDSS Collaboration