Regularities in averaged granulation patterns
-
Upload
gannon-avila -
Category
Documents
-
view
24 -
download
3
description
Transcript of Regularities in averaged granulation patterns
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