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Regularities in averaged granulation patterns

Regularities in averaged granulation patterns. Alexander V. Getling Institute of Nuclear Physics Lomonosov Moscow State University Moscow, 119992 Russia. La Palma series of photospheric images Brandt, Scharmer, & Simon, 5 June 1993 Swedish Vacuum Solar Telescope.

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Regularities in averaged granulation patterns

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  1. Regularities in averaged granulation patterns Alexander V. Getling Institute of Nuclear Physics Lomonosov Moscow State University Moscow, 119992 Russia

  2. La Palma series of photospheric imagesBrandt, Scharmer, & Simon, 5 June 1993Swedish Vacuum Solar Telescope • Spectral band: centre at 468 nm, width 10 nm • Duration: 11 h • Frame cadence: 21 s • Subset used here: time interval of duration 8 h • and subfield of size 43.5 × 43.5 Mm2 (60″ × 60″) • Resolution: no worse than 0.5 ″ • Contrast: 6–10.6 %

  3. Description of the series and data prereduction:G. W. Simon, P. N. Brandt,L. J. November, et. al. In Solar Surface Magnetism, eds. R. J. Rutten & C. J. Schrijver (Kluwer: Dordrecht, 1994), p. 261

  4. Data prereduction: • Alignment of contiguous images • LCT-based destretching (compensation for seeing-introduced distortions) • Subsonic Fourier filtering (cutoff phase speed of 4 km/s) • Fourier transform–based interpolation to equal time intervals

  5. Time averagingIndividual image 2-h-averaged image

  6. Target pattern of curved convection rollsExperiment:Assenheimer & Steinberg 1994

  7. Publications:A. V. Getling & P. N. Brandt • Astronomy and Astrophysics, 382 (1), L5–L8, 2002 • In Proc. 10th European Solar Physics Meeting “Solar Variability: From Core to Outer Frontiers”, Prague, Czech Republic, 9–14 September 2002 (ESA SP-506, December 2002), pp. 617–620

  8. Detection of lineaments,circular structures, and contours(nonparametric statistical criteria):A. A. Buchnev & V. P. PyatkinInstitute of Computational Mathematicsand Mathematical Geophysics,Novosibirsk

  9. The software packagewas developedto detect geological structuresin aerospace images

  10. Detection of lineaments and ringsfitting into frame(wide ranges of sizes)

  11. Detection of lineaments and ringsfitting into frame(narrower ranges of sizes)

  12. Detection of contours Contour = object with an unknown analytical representation Range of lengths: 16–24 px (pixel size: 0.125 ″; subfield: 480 × 480 px)

  13. Individual image Range of lengths: 32–240 px Averaged image Range of lengths: 16–240 px Angular distributions of lineaments

  14. Angular distribution of lineaments Range of lengths: 16–43 px

  15. Summary • In general, the software package detects mainly spurious circular structures • The angular distribution of the detected lineaments exhibits a strong anisotropy, despite many spurious features present • The detection of contours seems promising but requires a careful adjustment of the parameters

  16. Thank you for your attention

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