This describes the columns and flags in the CMF/SMF files, version PS1_V3. They are listed in source:trunk/psModules/src/objects/pmSourceIO_CMF_PS1_V3.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)
- CAL_PSF_MAG - calibrated PSF MAG
- CAL_PS_MAG_SIG - error
- RA_PSF - ra
- DEC_PSF - dec
- 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))
- 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_M3C - third moment cos theta:
- \Sum r^3 cos(3t) = \Sum r^3 (cos^3 t - r^2 3 cos t sin^2 t) = \Sum(x^3 - 3 x y^2) divided by \Sum (f_i) where r is radius from the centroid
- MOMENTS_M3S - third moment sin theta:
- \Sum r^3 sin(3t) = \Sum r^3 (3 cos^2 t sin t - sin^3 t = (3 x^2 y - y^3) divided by \Sum (f_i) where r is radius from the centroid
- MOMENTS_M4C - fourth moment cos theta:
- \Sum r^4 cos(4t) = \Sum r^4 (cos^4 t - r^2 6 cos^2 t sin^2 t + r^2 sin^4 t) = (x^4 - 6 x^2 y^2 + y^4) divided by \Sum (f_i) where r is radius from the centroid
- MOMENTS_M4S - fourth moment sin theta:
- \Sum r^4 sin(4t) = \Sum r^4 (4 cos^3 t sin t - 4 sin^3 t cos t) = (4 x^3 y - 4 y^3 x) divided by \Sum (f_i) where r is radius from the centroid
- 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)
- 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)
Values defined in psModules/src/objects/pmSourceMasks.h
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 |
0x0008.0000 | this bit is not defined | |
BIG_RADIUS | 0x0010.0000 | poor moments for small radius, try large radius |
AP_MAGS | 0x0020.0000 | source has an aperture magnitude |
BLEND_FIT | 0x0040.0000 | source was fitted as a blend |
EXTENDED_FIT | 0x0080.0000 | full extended fit was used |
EXTENDED_STATS | 0x0100.0000 | extended aperture stats calculated |
LINEAR_FIT | 0x0200.0000 | source fitted with the linear fit |
NONLINEAR_FIT | 0x0400.0000 | source fitted with the non-linear fit |
RADIAL_FLUX | 0x0800.0000 | radial flux measurements calculated |
SIZE_SKIPPED | 0x1000.0000 | Warning:: if set, size could be determined |
ON_SPIKE | 0x2000.0000 | peak lands on diffraction spike |
ON_GHOST | 0x4000.0000 | peak lands on ghost or glint |
OFF_CHIP | 0x8000.0000 | 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) |
ON_SPIKE | 0x0000.0008 | > 25% of (PSF-weighted) pixels land on diffraction spike |
ON_STARCORE | 0x0000.0010 | > 25% of (PSF-weighted) pixels land on star core |
ON_BURNTOOL | 0x0000.0020 | > 25% of (PSF-weighted) pixels land on burntool subtraction region |
ON_CONVPOOR | 0x0000.0040 | > 25% of (PSF-weighted) pixels land on region where convolution had substantial masked fraction contribution |
PASS1_SRC | 0x0000.0080 | source was detected in the first pass of psphot (bright detection stage) |
HAS_BRIGHTER_NEIGHBOR | 0x0000.0100 | peak is not the brightest in its footprint |
BRIGHT_NEIGHBOR_1 | 0x0000.0200 | flux_n / (r^{2 flux_p) > 1 } |
BRIGHT_NEIGHBOR_10 | 0x0000.0400 | flux_n / (r2 flux_p) > 10 |
DIFF_SELF_MATCH | 0x0000.0800 | positive detection match is probably this source |
SATSTAR_PROFILE | 0x0000.1000 | saturated source is modeled with a radial profile |