1. 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

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

3. 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)

4. SODISM Data Access
The function of SODISM is to continuously monitor solar activity.
Data used are W.L. 535nm images
L1B data access:

5. 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.

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

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

8. 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.

9. 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.

10. 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

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

12. 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 nm absorption spectral line, and were used to produce, amongst others, the intensitygrams and magnetograms.

13. An example for SOHO images and their segmented

14. correlation coefficient between the two data sets is 0.985

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

16. 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

17. Any Questions?
Thank you