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Astrometry in AW

Astrometry in AW. Overview of Astrometric processing. Astrometry in AW. Contents Ingest Diagnostics Single frame astrometry Diagnostics, Quality Control Global astrometry Diagnostics, Quality Control Super global astrometry Potential. Astrometry in AW. Ingest. Single. BiasFrame.

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Astrometry in AW

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

  2. 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

  3. Astrometry in AW Ingest Single BiasFrame RawScienceFrame FringeFrame SaturatedPixelMap MasterFlatFrame CosmicMap SatelliteMap IlluminationCorrection WeightFrame HotPixelMap ColdPixelMap Global ReducedScienceFrame GainLinearity AstrometricParameters PhotometricParameters RegriddedFrame CoaddedRegriddedFrame AstroWise Workshop 14 – 18 november 2005

  4. 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

  5. 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

  6. 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

  7. Ingest Astrometry • Where • Example www.astro-wise.org/portal -> dbview -> index of tables ->AstrometricCorrection -> select all AstroWise Workshop 14 – 18 november 2005

  8. 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

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

  10. 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

  11. Single frame astrometry ASTROM_KWLIST = [('VERBOSE', 'DEBUG'), ('NITER', 5), ('XMIN', 0.0), ('XMAX', 32767.0), ('YMIN', 0.0), ('YMAX', 32767.0), ('PDEG', 2), ('FDEG', [1, 0, 0]), ('XPIXSIZE', 1.000000), ('YPIXSIZE', 1.000000), ('# 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)] • 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) AstroWise Workshop 14 – 18 november 2005

  12. 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< 10.0. If these values are not reached, definitely something is wrong. 17:26:19 - LDAC: End of equation solution 0.000000 s iteration 0 17:26:19 - LDAC: Rms and max ref stars residuals for camera 0: 13.206169 and 57.039865 17:26:19 - LDAC: End of equation solution 0.000000 s iteration 1 17:26:19 - LDAC: Rms and max ref stars residuals for camera 0: 9.251933 and 38.200649 17:26:19 - LDAC: End of equation construction 0.001999 s iteration 2 17:26:19 - LDAC: Rms and max ref stars residuals for camera 0: 6.055043 and 27.733644 17:26:19 - LDAC: End of equation construction 0.002000 s iteration 3 17:26:19 - LDAC: Rms and max ref stars residuals for camera 0: 2.916056 and 17.896422 17:26:19 - LDAC: End of equation construction 0.001999 s iteration 4 17:26:19 - LDAC: Rms and max ref stars residuals for camera 0: 1.695296 and 8.931968 AstroWise Workshop 14 – 18 november 2005

  13. 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 17:26:19 - LDAC: Distortion coefficients for camera 0 17:26:19 - LDAC: (arcseconds) (radians) 17:26:19 - LDAC: -0.0007247 0.35 +/- 0.000173 -3.689e-06 0.001781 +/- 8.82e-07 X*1*Cheb0(F) 17:26:19 - LDAC: -0.3461 -0.0001404 +/- 4.24e-05 -0.001762 -7.149e-07 +/- 2.16e-07 1*Y*Cheb0(F) 17:26:19 - LDAC: -0.0004552 0.001882 +/- 6.17e-05 -2.317e-06 9.581e-06 +/- 3.14e-07 X**2*1*Cheb0(F) 17:26:19 - LDAC: -4.725e-05 0.0002249 +/- 2.84e-05 -2.405e-07 1.145e-06 +/- 1.44e-07 X*Y*Cheb0(F) 17:26:19 - LDAC: -0.0007643 0.0004423 +/- 1.56e-05 -3.891e-06 2.252e-06 +/- 7.92e-08 1*Y**2*Cheb0(F) X = -0.0007247 * x + 0.35 * y + -0.0004552 * x^2 + -4.725e-05 * x*y + -0.0007643 * y^2 and Y = -0.3461 * x + -0.0001404 * y + 0.001882 * x^2 + 0.0002249 * x*y + 0.0004423 * y^2 AstroWise Workshop 14 – 18 november 2005

  14. 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: 386 17:26:19 - 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: -0.000000 0.000000 -0.000096 0.033090 17:26:19 - LDAC: 1000 0 992 0 0 991 17:26:19 - LDAC: 0 1000 0 913 0 0 17:26:19 - LDAC: 992 0 1000 0 0 969 17:26:19 - LDAC: 0 913 0 0 0 0 17:26:19 - LDAC: 0 0 0 0 0 0 17:26:19 - LDAC: 991 0 969 0 0 1000 AstroWise Workshop 14 – 18 november 2005

  15. 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 tmp1118762778.2.cat1 -o tmp1118762778.2.cat7 -p tmp1118762778.2.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

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

  17. Single frame astrometry AstroWise Workshop 14 – 18 november 2005

  18. 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

  19. Single frame astrometry AstroWise Workshop 14 – 18 november 2005

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

  21. 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

  22. Global astrometry AstroWise Workshop 14 – 18 november 2005

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

  24. Global scaling parameter 4200 Distortion coefficients for camera 0 (arcseconds) (radians) -0.2404 0.003929 +/- 7.55e+09 -0.002448 4e-05 +/- 7.69e+07 X*1*Cheb0(F) 0.001794 0.236 +/- 6.65e+09 1.826e-05 0.002403 +/- 6.77e+07 1*Y*Cheb0(F) -0.0007422 0.0009733 +/- 1.16e+10 -7.557e-06 9.91e-06 +/- 1.18e+08 X**2*1*Cheb0(F) 0.0005092 -0.0005431 +/- 9.65e+09 5.185e-06 -5.529e-06 +/- 9.83e+07 X*Y*Cheb0(F) -0.0001865 0.0003967 +/- 1.05e+10 -1.899e-06 4.039e-06 +/- 1.07e+08 1*Y**2*Cheb0(F) Distortion coefficients for camera 1 (arcseconds) (radians) 0.003618 -0.003991 +/- 4.85e+09 3.683e-05 -4.063e-05 +/- 4.94e+07 1*1*Cheb0(F) -6.696e-05 6.302e-05 +/- 4.18e+09 -6.817e-07 6.416e-07 +/- 4.26e+07 1*1*Cheb1(F) -0.2349 2.26e-05 +/- 2.36e+09 -0.002391 2.301e-07 +/- 2.4e+07 X*1*Cheb0(F) 0.0005175 0.2376 +/- 5.88e+09 5.269e-06 0.002419 +/- 5.98e+07 1*Y*Cheb0(F) 0.001524 0.0001078 +/- 1.62e+09 1.551e-05 1.097e-06 +/- 1.65e+07 X**2*1*Cheb0(F) -0.0007697 -0.0001038 +/- 2.7e+09 -7.836e-06 -1.057e-06 +/- 2.75e+07 X*Y*Cheb0(F) -0.0004294 7.504e-05 +/- 9.44e+09 -4.372e-06 7.64e-07 +/- 9.61e+07 1*Y**2*Cheb0(F) Distortion coefficients for camera 2 (arcseconds) (radians) 0.002797 -0.004364 +/- 4.8e+09 2.847e-05 -4.443e-05 +/- 4.89e+07 1*1*Cheb0(F) -2.639e-05 2.842e-05 +/- 4.16e+09 -2.687e-07 2.894e-07 +/- 4.24e+07 1*1*Cheb1(F) -0.2375 1.304e-05 +/- 3.28e+09 -0.002418 1.328e-07 +/- 3.34e+07 X*1*Cheb0(F) 0.0007458 0.2382 +/- 6e+09 7.593e-06 0.002425 +/- 6.11e+07 1*Y*Cheb0(F) -0.001114 -0.001529 +/- 2.87e+09 -1.134e-05 -1.557e-05 +/- 2.92e+07 X**2*1*Cheb0(F) 0.0007405 0.001372 +/- 3.86e+09 7.54e-06 1.397e-05 +/- 3.93e+07 X*Y*Cheb0(F) -0.0004668 -0.0004421 +/- 9.86e+09 -4.753e-06 -4.501e-06 +/- 1e+08 1*Y**2*Cheb0(F) Distortion coefficients for camera 3 (arcseconds) (radians) -0.001454 -0.0007506 +/- 5.72e+09 -1.48e-05 -7.642e-06 +/- 5.82e+07 1*1*Cheb0(F) 1.491e-05 9.983e-06 +/- 4.97e+09 1.518e-07 1.016e-07 +/- 5.06e+07 1*1*Cheb1(F) -0.233 -0.003578 +/- 9.5e+09 -0.002372 -3.642e-05 +/- 9.67e+07 X*1*Cheb0(F) 0.001226 0.237 +/- 6.27e+09 1.248e-05 0.002413 +/- 6.38e+07 1*Y*Cheb0(F) -0.001313 0.0007651 +/- 1.65e+10 -1.337e-05 7.789e-06 +/- 1.68e+08 X**2*1*Cheb0(F) -0.0005989 0.001047 +/- 1.02e+10 -6.097e-06 1.066e-05 +/- 1.04e+08 X*Y*Cheb0(F) -0.0001621 -0.0003144 +/- 9.05e+09 -1.65e-06 -3.201e-06 +/- 9.21e+07 1*Y**2*Cheb0(F) Distortion coefficients for camera 4 (arcseconds) (radians) 0.01132 -0.003225 +/- 5.33e+09 0.0001153 -3.284e-05 +/- 5.42e+07 1*1*Cheb0(F) 7.777e-05 8.901e-05 +/- 4.76e+09 7.918e-07 9.062e-07 +/- 4.85e+07 1*1*Cheb1(F) -0.247 -5.187e-05 +/- 9.14e+09 -0.002515 -5.281e-07 +/- 9.3e+07 X*1*Cheb0(F) 0.001994 0.2382 +/- 5.03e+09 2.03e-05 0.002425 +/- 5.12e+07 1*Y*Cheb0(F) 0.002485 -0.0001676 +/- 1.64e+10 2.53e-05 -1.707e-06 +/- 1.67e+08 X**2*1*Cheb0(F) -0.00076 -0.0004328 +/- 8.58e+09 -7.738e-06 -4.406e-06 +/- 8.74e+07 X*Y*Cheb0(F) 0.0001683 -0.0001669 +/- 7.05e+09 1.714e-06 -1.699e-06 +/- 7.18e+07 1*Y**2*Cheb0(F) Distortion coefficients for camera 5 (arcseconds) (radians) 0.002081 -0.004482 +/- 5.48e+09 2.118e-05 -4.563e-05 +/- 5.58e+07 1*1*Cheb0(F) -3.707e-05 3.514e-05 +/- 4.81e+09 -3.775e-07 3.578e-07 +/- 4.9e+07 1*1*Cheb1(F) -0.2374 0.0002325 +/- 3.73e+09 -0.002417 2.368e-06 +/- 3.79e+07 X*1*Cheb0(F) 0.000211 0.2377 +/- 4.98e+09 2.148e-06 0.00242 +/- 5.07e+07 1*Y*Cheb0(F) -0.0002855 -0.0001358 +/- 3.15e+09 -2.907e-06 -1.383e-06 +/- 3.2e+07 X**2*1*Cheb0(F) 5.123e-05 9.773e-06 +/- 3.46e+09 5.216e-07 9.95e-08 +/- 3.52e+07 X*Y*Cheb0(F) 1.248e-06 -8.585e-06 +/- 6.84e+09 1.271e-08 -8.741e-08 +/- 6.97e+07 1*Y**2*Cheb0(F) Distortion coefficients for camera 6 (arcseconds) (radians) 0.002933 -0.004273 +/- 5.5e+09 2.986e-05 -4.35e-05 +/- 5.6e+07 1*1*Cheb0(F) -1.596e-05 9.679e-05 +/- 4.8e+09 -1.625e-07 9.855e-07 +/- 4.88e+07 1*1*Cheb1(F) -0.2372 3.946e-05 +/- 2.51e+09 -0.002415 4.017e-07 +/- 2.55e+07 X*1*Cheb0(F) -2.528e-05 0.2375 +/- 5.19e+09 -2.574e-07 0.002418 +/- 5.28e+07 1*Y*Cheb0(F) 0.000543 7.79e-05 +/- 1.63e+09 5.528e-06 7.931e-07 +/- 1.66e+07 X**2*1*Cheb0(F) -0.0001597 -5.25e-05 +/- 2.21e+09 -1.626e-06 -5.345e-07 +/- 2.25e+07 X*Y*Cheb0(F) -8.57e-05 -0.0001331 +/- 7.21e+09 -8.725e-07 -1.355e-06 +/- 7.34e+07 1*Y**2*Cheb0(F) Distortion coefficients for camera 7 (arcseconds) (radians) 0.003896 -0.002021 +/- 5.31e+09 3.967e-05 -2.058e-05 +/- 5.41e+07 1*1*Cheb0(F) -2.548e-05 6.096e-05 +/- 4.61e+09 -2.595e-07 6.206e-07 +/- 4.69e+07 1*1*Cheb1(F) -0.2361 0.002694 +/- 7.57e+09 -0.002404 2.743e-05 +/- 7.7e+07 X*1*Cheb0(F) 2.115e-05 0.2376 +/- 5.49e+09 2.154e-07 0.002419 +/- 5.59e+07 1*Y*Cheb0(F) 0.0007247 0.0007687 +/- 1.15e+10 7.378e-06 7.826e-06 +/- 1.17e+08 X**2*1*Cheb0(F) -0.000292 5.78e-06 +/- 7.81e+09 -2.973e-06 5.885e-08 +/- 7.95e+07 X*Y*Cheb0(F) 6.572e-05 -0.0001192 +/- 7.85e+09 6.691e-07 -1.214e-06 +/- 8e+07 1*Y**2*Cheb0(F) !Corrections to plate center coordinates (arcseconds) (radians) and plate center coordinates (radians) 1 -1.51 4.38 0.12 -7.3e-06 2.1e-05 6e-07 0.2076207 -0.5087055 6e-07 2 -1.71 4.42 0.12 -8.3e-06 2.1e-05 6e-07 0.2077600 -0.5086316 6e-07 3 -1.66 4.46 0.12 -8e-06 2.2e-05 6e-07 0.2080368 -0.5084848 6e-07 4 -1.83 4.23 0.12 -8.9e-06 2.1e-05 6e-07 0.2081750 -0.5084107 6e-07 5 -1.90 4.29 0.12 -9.2e-06 2.1e-05 6e-07 0.2078973 -0.5085568 6e-07 Number of reference stars: 3597 Number of overlap stars: 7935 AstroWise Workshop 14 – 18 november 2005

  25. Global astrometry AstroWise Workshop 14 – 18 november 2005

  26. Global astrometry AstroWise Workshop 14 – 18 november 2005

  27. Global astrometry AstroWise Workshop 14 – 18 november 2005

  28. Global astrometry AstroWise Workshop 14 – 18 november 2005

  29. Global astrometry AstroWise Workshop 14 – 18 november 2005

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

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

  32. 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

  33. Global astrometry • Quality Control • Solution accuracy • Reference objects • Errors on astrometric parameters • All stderr from solution • Number of reference stars < 0.3 arcsec /sqrt(Nref/PDEG) • Overlap pairs • Errors on astrometric parameters • All stderr from solution • Number of pairs • Offset among dither pointings < 0.1 arcsec /sqrt(Nover/PDEG) 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

  34. Global astrometry AstroWise Workshop 14 – 18 november 2005

  35. Global astrometry • Quality Control • Pre- and Post coadd PSF • Dithering cases sub-sampling -> sharper images • PSFregridded > PSFcoadded • No anisotropy AstroWise Workshop 14 – 18 november 2005

  36. 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

  37. 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

  38. 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 AstroWise Workshop 14 – 18 november 2005

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