AstroWise Workshop 14 – 18 november 2005 Astrometry in AW Overview of Astrometric processing

AstroWise Workshop 14 – 18 november 2005 Astrometry in AW Contents Ingest –Diagnostics Single frame astrometry –Diagnostics, Quality Control Global astrometry –Diagnostics, Quality Control Super global astrometry –Potential

AstroWise Workshop 14 – 18 november 2005 Single Global Ingest Astrometry in AW RawScienceFrameBiasFrame FringeFrame MasterFlatFrame IlluminationCorrection HotPixelMap ColdPixelMap GainLinearity PhotometricParameters ReducedScienceFrame CoaddedRegriddedFrame SatelliteMapCosmicMap RegriddedFrame SaturatedPixelMap WeightFrame AstrometricParameters

AstroWise Workshop 14 – 18 november 2005 Ingest Astrometry Why –Pointing problems –Large pointing offsets –Often small offsets –Unpredictable 0.5 – 1 image size Principally no limit

AstroWise Workshop 14 – 18 november 2005 Ingest Astrometry What –WFI data How –Frame based x-y grid Map all CCD x-y positions on one x-y grid A-priori knowledge of CCD chips on frame No rotation < few degrees Good knowledge of pixel scale (few percent) –opipe.astro.instrument.HeaderTranslatorWFI # Astrometric properties of the instrument. # CRPIX values for the chips in [CRPIX1, CRPIX2] format crpix_map = {'ccd50' : [ 4061., -223.], 'ccd51' : [ 1918., -222.], 'ccd52' : [ -226., -223.], 'ccd53' : [-2366., -222.], 'ccd54' : [-2364., 3904.], 'ccd55' : [ -215., 3899.], 'ccd56' : [ 1919., 3901.], 'ccd57' : [ 4061., 3898.]}

AstroWise Workshop 14 – 18 november 2005 Ingest Astrometry –Large offset determination (dx, dy) domain with large errorbars ~100 pixels –Application of offset –Refinement using triangulation method Offset Rotation Scale

AstroWise Workshop 14 – 18 november 2005 Ingest Astrometry Where –Example -> dbview -> index of tables ->AstrometricCorrection -> select all

AstroWise Workshop 14 – 18 november 2005 Ingest Astrometry –CD matrix CD1_1 = xx CD1_2 = xy CD2_1 = yx CD2_2 = yy –Update Astrom object –Product RawScienceFrame

AstroWise Workshop 14 – 18 november 2005 Single frame astrometry Standard pipeline reduction –Reduction per CCD –Overscan/Flat/Bias –Astrometry

AstroWise Workshop 14 – 18 november 2005 Single frame astrometry Pipeline processing single CCD’s –Input RawScienceFrame –Preastrom Pointing offset correction per CCD Small rotation/scaling correction Allow tight association extracted/reference objects –Astrom Single CCD astrometric solution

AstroWise Workshop 14 – 18 november 2005 Single frame astrometry Preastrom –Pointing offset correction –Small rotation/scaling correction –Allow tight association extracted/reference objects Astrom –PDEG=3 –opipe.astro.external.LDAC –opipe.astro.main.Astrom conf = LDAC.astromconf.get_kw_dict() conf[‘PDEG'] = 3 LDAC.astrom(incats, outcats, 'dither.pairs', 'dither.residuals', **conf) ASTROM_KWLIST = [('VERBOSE', 'DEBUG'), ('NITER', 5), ('XMIN', 0.0), ('XMAX', ), ('YMIN', 0.0), ('YMAX', ), ('PDEG', 2), ('FDEG', [1, 0, 0]), ('XPIXSIZE', ), ('YPIXSIZE', ), ('# DEFAULT USED: RA', None), ('# DEFAULT USED: DEC', None), ('# DEFAULT USED: ERR', None), ('# DEFAULT USED: XPOS', None), ('# DEFAULT USED: YPOS', None), ('# DEFAULT USED: FIELD', None), ('# DEFAULT USED: CAMERA', None), ('# DEFAULT USED: ERRPOS', None), ('# DEFAULT USED: XM2', None), ('# DEFAULT USED: YM2', None), ('# DEFAULT USED: CORR', None), ('# DEFAULT USED: CRVAL1', None), ('# DEFAULT USED: CRVAL2', None), ('# DEFAULT USED: CRPIX1', None), ('# DEFAULT USED: CRPIX2', None), ('# DEFAULT USED: CDELT1', None), ('# DEFAULT USED: CDELT2', None), ('# DEFAULT USED: XWID', None), ('# DEFAULT USED: YWID', None), ('# DEFAULT USED: EPOCH', None), ('# DEFAULT USED: DATA_TYPE', None)]

AstroWise Workshop 14 – 18 november 2005 Single frame astrometry Diagnostisc –Log Throught the iteration sequence the Rms and max values should decrease to smaller values to end up Rms< 2.5 and max< If these values are not reached, definitely something is wrong. 17:26:19 - LDAC: End of equation solution s iteration 0 17:26:19 - LDAC: Rms and max ref stars residuals for camera 0: and :26:19 - LDAC: End of equation solution s iteration 1 17:26:19 - LDAC: Rms and max ref stars residuals for camera 0: and :26:19 - LDAC: End of equation construction s iteration 2 17:26:19 - LDAC: Rms and max ref stars residuals for camera 0: and :26:19 - LDAC: End of equation construction s iteration 3 17:26:19 - LDAC: Rms and max ref stars residuals for camera 0: and :26:19 - LDAC: End of equation construction s iteration 4 17:26:19 - LDAC: Rms and max ref stars residuals for camera 0: and

AstroWise Workshop 14 – 18 november 2005 Single frame astrometry Diagnostisc –Log First column contains X related solution, second column Y related solution. So here the WCS is a rotated one Third column gives solution errors X = * x * y * x^ e-05 * x*y * y^2 and Y = * x * y * x^ * x*y * y^2 17:26:19 - LDAC: Distortion coefficients for camera 0 17:26:19 - LDAC: (arcseconds) (radians) 17:26:19 - LDAC: / e /- 8.82e-07 X*1*Cheb0(F) 17:26:19 - LDAC: /- 4.24e e-07 +/- 2.16e-07 1*Y*Cheb0(F) 17:26:19 - LDAC: /- 6.17e e e-06 +/- 3.14e-07 X**2*1*Cheb0(F) 17:26:19 - LDAC: e /- 2.84e e e-06 +/- 1.44e-07 X*Y*Cheb0(F) 17:26:19 - LDAC: /- 1.56e e e-06 +/- 7.92e-08 1*Y**2*Cheb0(F)

AstroWise Workshop 14 – 18 november 2005 Single frame astrometry Diagnostisc –Correlation matrix The number of reference stars large for a good solution. 6 Free parameters, -> 12 pairs for statistical accuracy. In general < 50 is not so good. The correlation matrix highest values on diagonal and all 0 on the other positions. X related and Y related parameters are correlated, but there should not be any cross dependencies between X and Y. Matrix is ordered: (X, Y, X**2, X*Y, Y**2). Offset with the columns direction X related solutions and rows direction Y related solutions. 17:26:19 - LDAC: Number of reference stars: :26:19 - LDAC: Number of overlap stars: 0 17:26:19 - LDAC: Min and Max of covariance matrix: 17:26:19 - LDAC: (radians)**2 (")**2 17:26:19 - LDAC: :26:19 - LDAC: :26:19 - LDAC: :26:19 - LDAC: :26:19 - LDAC: :26:19 - LDAC: :26:19 - LDAC:

AstroWise Workshop 14 – 18 november 2005 Single frame astrometry Diagnostics –Residuals catalog Original astrom call Extract to ascii catalog: The ascii catalog contains the residuals in Ra,Dec, the Ra and Dec of the extracted object and the X,Y coordinates of the reference and extracted objects (Note only true in case of pipeline astrom, not so for Global Astrom) astrom -i tmp cat1 -o tmp cat7 -p tmp cat6 -c astrom.conf -r ldac.ast.cat.residuals ldactoasc -i ldac.ast.cat.residuals -t RESIDUALS -k DRa DDec Ra Dec Xpos1 Ypos1 Xpos2 Ypos2 > res.asc

AstroWise Workshop 14 – 18 november 2005 Single frame astrometry Diagnostics -Plots

AstroWise Workshop 14 – 18 november 2005 Single frame astrometry

AstroWise Workshop 14 – 18 november 2005 Single frame astrometry Quality Control –Positional accuracy Reference catalog (USNO) –0.3 arcsec on large scales –0.15 arcsec on small scales (relative) Extracted object Reference stars –RMS extracted objects 0.1 arcsec at 5 σ –RMS residuals at 5 σ < 0.5 arcsec –Max residuals < 1.5 arcsec –Solution accuracy Errors on astrometric parameters All stderr from solution Number of reference stars MEAN_DRA MEAN_DDEC SIG_DRA SIG_DDEC NREF x_err y_err xx_err xy_err yy_err field_err

AstroWise Workshop 14 – 18 november 2005 Single frame astrometry

AstroWise Workshop 14 – 18 november 2005 Single frame astrometry Product – RegriddedFrame AstrometricParameters –Full astrometric solution

AstroWise Workshop 14 – 18 november 2005 Global astrometry What –Set of overlapping pointings -d : date (in yyyy-mm-dd format) -c : chip name -f : filter name -i : instrument name -o : object name (full name or regular expression) -g : AssociationListName –Equal camera/CCD’s –Irrelavant: filters, number of pointings GAstrom –GAstrometric Set of sourcelists lists One associate list

AstroWise Workshop 14 – 18 november 2005 Global astrometry

AstroWise Workshop 14 – 18 november 2005 Global astrometry Input –ReducedScienceFrame Product –RegriddedFrame Astrometric Parameters –Full astrometric solution

AstroWise Workshop 14 – 18 november 2005 Global scaling parameter 4200 Distortion coefficients for camera 0 (arcseconds) (radians) /- 7.55e e-05 +/- 7.69e+07 X*1*Cheb0(F) /- 6.65e e /- 6.77e+07 1*Y*Cheb0(F) /- 1.16e e e-06 +/- 1.18e+08 X**2*1*Cheb0(F) /- 9.65e e e-06 +/- 9.83e+07 X*Y*Cheb0(F) /- 1.05e e e-06 +/- 1.07e+08 1*Y**2*Cheb0(F) Distortion coefficients for camera 1 (arcseconds) (radians) /- 4.85e e e-05 +/- 4.94e+07 1*1*Cheb0(F) e e-05 +/- 4.18e e e-07 +/- 4.26e+07 1*1*Cheb1(F) e-05 +/- 2.36e e-07 +/- 2.4e+07 X*1*Cheb0(F) /- 5.88e e /- 5.98e+07 1*Y*Cheb0(F) /- 1.62e e e-06 +/- 1.65e+07 X**2*1*Cheb0(F) /- 2.7e e e-06 +/- 2.75e+07 X*Y*Cheb0(F) e-05 +/- 9.44e e e-07 +/- 9.61e+07 1*Y**2*Cheb0(F) Distortion coefficients for camera 2 (arcseconds) (radians) /- 4.8e e e-05 +/- 4.89e+07 1*1*Cheb0(F) e e-05 +/- 4.16e e e-07 +/- 4.24e+07 1*1*Cheb1(F) e-05 +/- 3.28e e-07 +/- 3.34e+07 X*1*Cheb0(F) /- 6e e /- 6.11e+07 1*Y*Cheb0(F) /- 2.87e e e-05 +/- 2.92e+07 X**2*1*Cheb0(F) /- 3.86e e e-05 +/- 3.93e+07 X*Y*Cheb0(F) /- 9.86e e e-06 +/- 1e+08 1*Y**2*Cheb0(F) Distortion coefficients for camera 3 (arcseconds) (radians) /- 5.72e e e-06 +/- 5.82e+07 1*1*Cheb0(F) 1.491e e-06 +/- 4.97e e e-07 +/- 5.06e+07 1*1*Cheb1(F) /- 9.5e e-05 +/- 9.67e+07 X*1*Cheb0(F) /- 6.27e e /- 6.38e+07 1*Y*Cheb0(F) /- 1.65e e e-06 +/- 1.68e+08 X**2*1*Cheb0(F) /- 1.02e e e-05 +/- 1.04e+08 X*Y*Cheb0(F) /- 9.05e e e-06 +/- 9.21e+07 1*Y**2*Cheb0(F) Distortion coefficients for camera 4 (arcseconds) (radians) /- 5.33e e-05 +/- 5.42e+07 1*1*Cheb0(F) 7.777e e-05 +/- 4.76e e e-07 +/- 4.85e+07 1*1*Cheb1(F) e-05 +/- 9.14e e-07 +/- 9.3e+07 X*1*Cheb0(F) /- 5.03e e /- 5.12e+07 1*Y*Cheb0(F) /- 1.64e e e-06 +/- 1.67e+08 X**2*1*Cheb0(F) /- 8.58e e e-06 +/- 8.74e+07 X*Y*Cheb0(F) /- 7.05e e e-06 +/- 7.18e+07 1*Y**2*Cheb0(F) Distortion coefficients for camera 5 (arcseconds) (radians) /- 5.48e e e-05 +/- 5.58e+07 1*1*Cheb0(F) e e-05 +/- 4.81e e e-07 +/- 4.9e+07 1*1*Cheb1(F) /- 3.73e e-06 +/- 3.79e+07 X*1*Cheb0(F) /- 4.98e e /- 5.07e+07 1*Y*Cheb0(F) /- 3.15e e e-06 +/- 3.2e+07 X**2*1*Cheb0(F) 5.123e e-06 +/- 3.46e e e-08 +/- 3.52e+07 X*Y*Cheb0(F) 1.248e e-06 +/- 6.84e e e-08 +/- 6.97e+07 1*Y**2*Cheb0(F) Distortion coefficients for camera 6 (arcseconds) (radians) /- 5.5e e e-05 +/- 5.6e+07 1*1*Cheb0(F) e e-05 +/- 4.8e e e-07 +/- 4.88e+07 1*1*Cheb1(F) e-05 +/- 2.51e e-07 +/- 2.55e+07 X*1*Cheb0(F) e /- 5.19e e /- 5.28e+07 1*Y*Cheb0(F) e-05 +/- 1.63e e e-07 +/- 1.66e+07 X**2*1*Cheb0(F) e-05 +/- 2.21e e e-07 +/- 2.25e+07 X*Y*Cheb0(F) -8.57e /- 7.21e e e-06 +/- 7.34e+07 1*Y**2*Cheb0(F) Distortion coefficients for camera 7 (arcseconds) (radians) /- 5.31e e e-05 +/- 5.41e+07 1*1*Cheb0(F) e e-05 +/- 4.61e e e-07 +/- 4.69e+07 1*1*Cheb1(F) /- 7.57e e-05 +/- 7.7e+07 X*1*Cheb0(F) 2.115e /- 5.49e e /- 5.59e+07 1*Y*Cheb0(F) /- 1.15e e e-06 +/- 1.17e+08 X**2*1*Cheb0(F) e-06 +/- 7.81e e e-08 +/- 7.95e+07 X*Y*Cheb0(F) 6.572e /- 7.85e e e-06 +/- 8e+07 1*Y**2*Cheb0(F) !Corrections to plate center coordinates (arcseconds) (radians) and plate center coordinates (radians) e e-05 6e e e e-05 6e e e e-05 6e e e e-05 6e e e e-05 6e e-07 Number of reference stars: 3597 Number of overlap stars: 7935

AstroWise Workshop 14 – 18 november 2005 Global astrometry

AstroWise Workshop 14 – 18 november 2005 Global astrometry

AstroWise Workshop 14 – 18 november 2005 Global astrometry

AstroWise Workshop 14 – 18 november 2005 Global astrometry

AstroWise Workshop 14 – 18 november 2005 Global astrometry

AstroWise Workshop 14 – 18 november 2005 Global astrometry Product – RegriddedFrame AstrometricParameters

AstroWise Workshop 14 – 18 november 2005 Global astrometry Final product –CoaddRegiddedFrame Selection list for Coadd must/may be equal to GAstrom

AstroWise Workshop 14 – 18 november 2005 Global astrometry Quality Control –Positional accuracy Reference catalog (USNO) –0.3 arcsec on large scales –0.15 arcsec on small scales (relative) Extracted object Reference stars –RMS extracted objects 0.1 arcsec at 5 σ –RMS residuals < 0.5 arcsec –Max residuals < 1.5 arcsec Extracted object Extracted objects –RMS extracted objects 0.1 arcsec at 5 σ –RMS residuals < 0.2 arcsec –Max residuals < 0.6 arcsec MEAN_DRA MEAN_DDEC SIG_DRA SIG_DDEC

AstroWise Workshop 14 – 18 november 2005 Global astrometry Quality Control –Solution accuracy Reference objects –Errors on astrometric parameters –All stderr from solution –Number of reference stars < 0.3 arcsec /sqrt(N ref /P DEG ) Overlap pairs –Errors on astrometric parameters –All stderr from solution –Number of pairs –Offset among dither pointings < 0.1 arcsec /sqrt(N over /P DEG ) NREF x_err y_err xx_err xy_err yy_err (xxx_err xxy_err xyy_err yyy_err) field_err

AstroWise Workshop 14 – 18 november 2005 Global astrometry

AstroWise Workshop 14 – 18 november 2005 Global astrometry Quality Control –Pre- and Post coadd PSF Dithering cases sub-sampling -> sharper images PSF regridded > PSF coadded No anisotropy

AstroWise Workshop 14 – 18 november 2005 Super global astrometry Potential solution sky-wise –Database stores Sourcelists Relations, creation history –Separate into distinct, independent effects Instrument –Chips on baseplate –Litho masks Camera –Mounting, filters, ADC Telescope –Pointing, remount/resurface, reconstruct

AstroWise Workshop 14 – 18 november 2005 Super global astrometry Potential solution sky-wise –Variability of effects Constant elements –Chips mounted on base Time evolution Discontinuities –(un)mounting parts of instrument/camera/telescope Relations with ambient –Temperature –Humidity

AstroWise Workshop 14 – 18 november 2005 Super global astrometry Potential solution sky-wise –Error budget RMS position extracted sources 0.1 * pixelsize= 0.02 arcsec Overlap statistics: # sources x # overlaps Fixed frame (whole sky) of overlapped pointings Connect to astrometric reference catalog –Characteristics Large scale and small scale high precision Use more precise less dense astrometric catalogs: Hipparcos <0.001 arcs, Tycho <0.03 arcsec