Automatic Sunspots Detection in SODISM Solar Images Mr Amro Alasta Prof Rami Qahwaji Dr Stan Ipson School of Engineering and Informatics, Bradford University Richmond Road, Bradford BD7 1DP, UK

Outlines PICARD satellite . Introduction. PICARD satellite . Solar Diameter Imager and Surface Mapper (SODISM) Methodology results. Conclusion & Recommendation.

Introduction France launched the PICARD satellite on 15 June 2010. PICARD Observes solar activity using the Solar Diameter Imager and Surface Mapper (SODISM). SODISM has five bands (215nm, 393nm, 535nm, 607nm and 782nm)

SODISM Data Access The function of SODISM is to continuously monitor solar activity. Data used are W.L. 535nm images L1B data access: http://picard.projet.latmos.ipsl.fr/files.php

SODISM Data Access The number of images used is 206 images. The format of these image files is FITS and each image has a size of 2048× 2048 pixels.

Pre-processing and method detect the solar disk Convert the image scale Kuwahara and Atrous filters. Band pass filter. Threshold

Results A SODISM 535 image from 12:30, 1th October 2011 and resulting detected sunspots

Filling factors filling factor is calculated as a function of radial position on the sun disk. The solar disk is divided by 11 concentric rings starting with an inner radius RI and an outer radius RO.

Filling Factor The calculated filling factors for a feature reflect the fraction of the solar disk covered by the feature and the assignment of reference synthetic spectra. The filling factor can be used for result assessment, by comparing the results with others satellites results such as SOHO.

An example for Sunspot in the different parts of the solar Index Inner radius Outer radius Sunspots 1 0.07 2 0.16 3 0.25 4 0.35 5 0.45 1170 6 0.55 7 0.65 8 0.75 18.55 9 0.85 94.45 10 0.95 338 11 1.05 Total of Pixels 1621

Results comparison between sunspots’ filling factors calculated for SODISM 535 nm images and MDI intensitygram images from the SOHO satellite has been done.

SOHO The Solar Oscillations Investigation/ Michelson Doppler Imager on board of the Solar and Heliospheric Observatory (SOHO) satellite took sets of high quality full-disk images. The images were taken using five narrow-band filters through the 676.8 nm absorption spectral line, and were used to produce, amongst others, the intensitygrams and magnetograms.

An example for SOHO images and their segmented

correlation coefficient between the two data sets is 0.985

Sunspot filling factors calculated for 535 images over the lifetime of the satellite

Conclusions The method adopted here successfully detects sunspots on 535 nm images over the lifetime of the satellite and then calculates their filling factors. filling factors between SOHO and SODSIM images shows an excellent match 0.985.

Any Questions? Thank you