This describes the columns and flags in the CMF/SMF files, version PS1_DV2 defined in source:trunk/psModules/src/objects/pmSourceIO_CMF_PS1_DV2.c. This is a slightly more descriptive version.

Columns

• IPP_IDET - detection id (increment from 0 per chip - gaps are from magic)
• X_PSF -position (in pixels
• Y_PSF -position in pixels
• X_PSF_SIGMA -position sigma
• Y_PSF_SIGMA -position sigma
• POSANGLE - position angle of the instrument coordinate system at source (ie, the angle between north and the y-axis) in degrees
• PLTSCALE - plate-scale at the source position (it varies across the exposure!) in arcsec
• PSF_INST_MAG - PSF Instrumental mag
• PSF_INST_MAG_SIG - error for that
• PSF_INST_FLUX
• PSF_INST_FLUX_SIG
• AP_MAG - aperture mag
• AP_MAG_RAW
• AP_MAG_RADIUS - aperture mag radius (pixels)
• AP_FLUX - counts
• AP_FLUX_SIG - error on previous
• PEAK_FLUX_AS_MAG - as it says, it is the flux (counts/pixel) for the peak pixel expressed as an instrumental magnitude (-2.5*log(flux))
• CAL_PSF_MAG - calibrated PSF MAG
• CAL_PS_MAG_SIG - error
• RA_PSF - ra
• DEC_PSF - dec
• SKY - background in counts (DN, not electrons)
• SKY_SIGMA -error
• PSF_CHISQ - chisq of psf
• CR_NSIGMA - cosmic ray
• EXT_NSIGMA - extended source
• PSF_MAJOR - major axis (pixel)
• PSF_MINOR - minor axis (pixel)
• PSF_THETA - angle
• PSF_QF - the psf-weighted fraction of unmasked pixels:
  • \Sum_i (psf_i * !masked) / \Sum_i (psf_i)
• PSF_QF_PERFECT - the psf-weighted fraction of unmasked pixels (including suspect pixels):
  • \Sum_i (psf_i * !masked) / \Sum_i (psf_i)
• PSF_NDOF - number of degrees of freedom for the fit -- for the diff detections, the only free parameter is the flux, so N_DOF = N_PIX - 1; in other cases, there may be more parameters (eg, position, size, etc).
• PSF_NPIX - number of pixels for fit
• MOMENTS_XX - second moment in x:
  • \Sum ((x_i - x_o)^2 f_i) / \Sum (f_i) where x_o is the centroid \Sum (x_i f_i) / \Sum f_i
• MOMENTS_XY - second moment in xy:
  • \Sum ((x_i - x_o)(y_i - y_o)^2 f_i) / \Sum (f_i)
• MOMENTS_YY - second moment in xy
  • \Sum ((y_i - y_o)^2 f_i) / \Sum (f_i)

• MOMENTS_R1 - first radial moment (used to define the Kron radius = 2.5 R1)
  • \Sum r f_i) / \Sum (f_i) where r is radius from the centroid
• MOMENTS_RH - half radial moment (an indicator of concentration)
  • \Sum sqrt(r) f_i) / \Sum (f_i) where r is radius from the centroid
• KRON_FLUX - flux within Kron Radius (2.5 * first radial moment)
• KRON_FLUX_ERR - error on the above

• KRON_FLUX_INNER - flux within annulus (1.0 R1 < R < 2.5 R1)
• KRON_FLUX_OUTER - flux within annulus (2.5 R1 < R < 4.0 R1)

• DIFF_NPOS - nPos (n pix > 0.0 flux)
• DIFF_FRATIO - fPos / (fPos + fNeg) where fPos = \Sum (f_i) if f_i > 0.0, and fNeg = \Sum (f_i) if f_i < 0.0
• DIFF_NRATIO_BAD - nPos / (nPos + nNeg) where nPos = number of pixels with f_i > 0.0, and nNeg = number of pixels with f_i < 0.0
• DIFF_NRATIO_MASK - nPos / (nPos + nMask) where nMask = number of masked pixels
• DIFF_NRATIO_ALL - nPos / (nGood + nMask + nNeg)

• DIFF_R_P - distance to matched source in positive image
• DIFF_SN_P - signal-to-noise of matched source in positive image
• DIFF_R_M - distance to matched source in negative image
• DIFF_SN_M - signal-to-noise of matched source in negative image

• FLAGS - see below
• FLAGS2 - see below

• N_FRAMES - this is not currently set, but it is supposed to have the value of the number of input images overlapping the center of the source (for warp-warp diff, it would be 2, for a single image it would be 1, for a stack it may be something else).
• PADDING - a dummy block of data needed to fit the rows into 8-byte boundaries (this lets me read into structures as a bulk byte read operation).

FLAGS

(see also [wiki:IPP_Detection_Bitmasks)

DEFAULT	0x0000.0000	Initial value: resets all bits
PSFMODEL	0x0000.0001	Source fitted with a psf model (linear or non-linear)
EXTMODEL	0x0000.0002	Source fitted with an extended-source model
FITTED	0x0000.0004	Source fitted with non-linear model (PSF or EXT; good or bad)
FITFAIL	0x0000.0008	Fit (non-linear) failed (non-converge, off-edge, run to zero)
POORFIT	0x0000.0010	Fit succeeds, but low-SN, high-Chisq, or large (for PSF -- drop?)
PAIR	0x0000.0020	Source fitted with a double psf
PSFSTAR	0x0000.0040	Source used to define PSF model
SATSTAR	0x0000.0080	Source model peak is above saturation
BLEND	0x0000.0100	Source is a blend with other sourcers
EXTERNALPOS"	0x0000.0200	Source based on supplied input position
BADPSF	0x0000.0400	Failed to get good estimate of object's PSF
DEFECT	0x0000.0800	Source is thought to be a defect
SATURATED	0x0000.1000	Source is thought to be saturated pixels (bleed trail)
CR_LIMIT	0x0000.2000	Source has crNsigma above limit
EXT_LIMIT	0x0000.4000	Source has extNsigma above limit
MOMENTS_FAILURE	0x0000.8000	could not measure the moments
SKY_FAILURE	0x0001.0000	could not measure the local sky
SKYVAR_FAILURE	0x0002.0000	could not measure the local sky variance
MOMENTS_SN	0x0004.0000	moments not measured due to low S/N
BIG_RADIUS	0x0008.0000	poor moments for small radius, try large radius
AP_MAGS	0x0010.0000	source has an aperture magnitude
BLEND_FIT	0x0020.0000	source was fitted as a blend
EXTENDED_FIT	0x0040.0000	full extended fit was used
EXTENDED_STATS	0x0080.0000	extended aperture stats calculated
LINEAR_FIT	0x0100.0000	source fitted with the linear fit
NONLINEAR_FIT	0x0200.0000	source fitted with the non-linear fit
RADIAL_FLUX	0x0400.0000	radial flux measurements calculated
SIZE_SKIPPED	0x0800.0000	size could not be determined
ON_SPIKE	0x1000.0000	peak lands on diffraction spike
ON_GHOST	0x2000.0000	peak lands on ghost or glint
OFF_CHIP	0x4000.0000	peak lands off edge of chip

FLAGS2

DIFF_WITH_SINGLE	0x0000.0001	diff source matched to a single positive detection
DIFF_WITH_DOUBLE	0x0000.0002	diff source matched to positive detections in both images
MATCHED	0x0000.0004	source was supplied at this location from somewhere else (eg, another image, forced photometry location, etc)