Regularities in averaged granulation patterns

Alexander V. GetlingAlexander V. Getling

Institute of Nuclear PhysicsInstitute of Nuclear Physics

Lomonosov Moscow State UniversityLomonosov Moscow State University

Moscow, 119992 RussiaMoscow, 119992 Russia

La Palma series of photospheric images

Brandt, Scharmer, & Simon, 5 June 1993Swedish Vacuum Solar Telescope

Spectral band: centre at 468 nm, width 10 nmSpectral band: centre at 468 nm, width 10 nm Duration: 11 hDuration: 11 h Frame cadence: 21 sFrame cadence: 21 s Subset Subset used here:used here: time interval of duration 8 h time interval of duration 8 h andand subfield of size 43.5 subfield of size 43.5 × 43.5 Mm× 43.5 Mm2 2 (60(60″ ″ ×× 60 60″″)) Resolution: no worse than 0.5 Resolution: no worse than 0.5 ″″ Contrast: 6Contrast: 6––10.6 %10.6 %

Description of the series and data prereduction:

G. W. Simon, P. N. Brandt,L. J. November, et. al.

In In Solar Surface MagnetismSolar Surface Magnetism,,

eds. R. J. Rutten & C. J. Schrijvereds. R. J. Rutten & C. J. Schrijver

(Kluwer: Dordrecht, 1994), p. 261(Kluwer: Dordrecht, 1994), p. 261

Data prereduction:

Alignment of contiguous imagesAlignment of contiguous images LCT-based destretching (compensation for LCT-based destretching (compensation for

seeing-introduced distortions)seeing-introduced distortions) Subsonic Fourier filtering Subsonic Fourier filtering

(cutoff phase speed of 4 km/s)(cutoff phase speed of 4 km/s) Fourier transformFourier transform––based interpolation to based interpolation to

equal time intervalsequal time intervals

Time averaging Individual image 2-h-averaged image

Target pattern of curved convection rolls

Experiment:Assenheimer & Steinberg 1994

Publications:

A. V. Getling & P. N. Brandt

Astronomy and Astrophysics, Astronomy and Astrophysics, 382382 (1), (1), L5–L8, 2002L5–L8, 2002

In In Proc. 10th European Solar Physics Proc. 10th European Solar Physics Meeting “Solar Variability: From Core to Meeting “Solar Variability: From Core to Outer Frontiers”Outer Frontiers”, Prague, Czech Republic, , Prague, Czech Republic, 9–14 September 2002 (9–14 September 2002 (ESA SP-506ESA SP-506, , December 2002), pp. 617–620December 2002), pp. 617–620

Detection of lineaments,circular structures, and contours

(nonparametric statistical criteria):

A. A. Buchnev & V. P. Pyatkin

Institute of Computational Mathematicsand Mathematical Geophysics,

Novosibirsk

The software packagewas developed

to detect geological structuresin aerospace images

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

Detection of lineaments and ringsfitting into frame

(narrower ranges of sizes)

Detection of contours

ContourContour = object with = object with

an an unknown analyticalunknown analytical

representationrepresentation

Range of lengths: 16Range of lengths: 16––224 px4 px

(pixel size: 0.125 (pixel size: 0.125 ″″;;subfield: 480 × 480 px)subfield: 480 × 480 px)

Angular distributions of lineaments

Individual imageIndividual imageRange of lengths: 32Range of lengths: 32––240 px240 px

Averaged imageAveraged imageRange of lengths: 16Range of lengths: 16––2240 px40 px

Angular distribution of lineaments

Range of lengths: 16Range of lengths: 16––43 px43 px

Summary

In general, the software package detects In general, the software package detects mainly spurious mainly spurious circular structurescircular structures

The angular distribution of the detected The angular distribution of the detected lineamentslineaments exhibits exhibits a strong anisotropya strong anisotropy, , despite many spurious features presentdespite many spurious features present

The detection of The detection of contourscontours seems promising seems promising but requires a careful adjustment of the but requires a careful adjustment of the parametersparameters

Thank you for your attention