Preliminary Results on Irradiance Measurements from Lyra and Swap
The first and preliminary results of the photometry of Large Yield Radiometer (LYRA) and Sun Watcher using Active Pixel system detector and Image Processing (SWAP) onboard PROBA2 are presented in this paper. To study the day-to-day variations of LYRA irradiance, we have compared the LYRA irradiance...
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2012-01-01
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| Series: | Advances in Astronomy |
| Online Access: | http://dx.doi.org/10.1155/2012/623709 |
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| author | S. T. Kumara R. Kariyappa M. Dominique D. Berghmans L. Damé J. F. Hochedez V. H. Doddamani Lakshmi Pradeep Chitta |
| author_facet | S. T. Kumara R. Kariyappa M. Dominique D. Berghmans L. Damé J. F. Hochedez V. H. Doddamani Lakshmi Pradeep Chitta |
| author_sort | S. T. Kumara |
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| description | The first and preliminary results of the photometry of Large Yield Radiometer (LYRA) and Sun Watcher using Active Pixel system detector and Image Processing (SWAP) onboard PROBA2 are presented in this paper. To study the day-to-day variations of LYRA irradiance, we have
compared the LYRA irradiance values (observed Sun as a star) measured in Aluminum filter channel (171 Å–500 Å) with spatially resolved full-disk integrated intensity values measured with SWAP (174 Å) and Ca II K 1 Å index values (ground-based observations from NSO/Sac Peak) for
the period from 01 April 2010 to 15 Mar 2011. We found that there is a good correlation between these parameters. This indicates that the spatial resolution of SWAP complements the high temporal resolution of LYRA. Hence SWAP can be considered as an additional radiometric channel. Also the K emission index is the integrated intensity (or flux) over a 1 Å band centered on the K line and is proportional to the total emission from the chromosphere; this comparison clearly explains that the LYRA irradiance variations are due to the various magnetic features, which are contributing significantly. In addition to this we have made an attempt to segregate coronal features from full-disk SWAP images. This will help to understand and determine the actual contribution of the individual coronal feature to LYRA irradiance variations. |
| format | Article |
| id | doaj-art-8f2712ceac7844b68f3e03d5d36f3f6a |
| institution | Kabale University |
| issn | 1687-7969 1687-7977 |
| language | English |
| publishDate | 2012-01-01 |
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| series | Advances in Astronomy |
| spelling | doaj-art-8f2712ceac7844b68f3e03d5d36f3f6a2025-02-03T06:00:04ZengWileyAdvances in Astronomy1687-79691687-79772012-01-01201210.1155/2012/623709623709Preliminary Results on Irradiance Measurements from Lyra and SwapS. T. Kumara0R. Kariyappa1M. Dominique2D. Berghmans3L. Damé4J. F. Hochedez5V. H. Doddamani6Lakshmi Pradeep Chitta7Department of Physics, Auden Technology and Management Academy (ATMA), Bangalore 562112, IndiaIndian Institute of Astrophysics, Bangalore 560 034, IndiaRoyal Observatory of Belgium (ROB), Circular Avenue 3, B-1180 Brussels, BelgiumRoyal Observatory of Belgium (ROB), Circular Avenue 3, B-1180 Brussels, BelgiumLATMOS, 11 Boulevard d'Alembert, 78280 Guyancourt, FranceLATMOS, 11 Boulevard d'Alembert, 78280 Guyancourt, FranceDepartment of Physics, Bangalore University, Bangalore 560056, IndiaIndian Institute of Astrophysics, Bangalore 560 034, IndiaThe first and preliminary results of the photometry of Large Yield Radiometer (LYRA) and Sun Watcher using Active Pixel system detector and Image Processing (SWAP) onboard PROBA2 are presented in this paper. To study the day-to-day variations of LYRA irradiance, we have compared the LYRA irradiance values (observed Sun as a star) measured in Aluminum filter channel (171 Å–500 Å) with spatially resolved full-disk integrated intensity values measured with SWAP (174 Å) and Ca II K 1 Å index values (ground-based observations from NSO/Sac Peak) for the period from 01 April 2010 to 15 Mar 2011. We found that there is a good correlation between these parameters. This indicates that the spatial resolution of SWAP complements the high temporal resolution of LYRA. Hence SWAP can be considered as an additional radiometric channel. Also the K emission index is the integrated intensity (or flux) over a 1 Å band centered on the K line and is proportional to the total emission from the chromosphere; this comparison clearly explains that the LYRA irradiance variations are due to the various magnetic features, which are contributing significantly. In addition to this we have made an attempt to segregate coronal features from full-disk SWAP images. This will help to understand and determine the actual contribution of the individual coronal feature to LYRA irradiance variations.http://dx.doi.org/10.1155/2012/623709 |
| spellingShingle | S. T. Kumara R. Kariyappa M. Dominique D. Berghmans L. Damé J. F. Hochedez V. H. Doddamani Lakshmi Pradeep Chitta Preliminary Results on Irradiance Measurements from Lyra and Swap Advances in Astronomy |
| title | Preliminary Results on Irradiance Measurements from Lyra and Swap |
| title_full | Preliminary Results on Irradiance Measurements from Lyra and Swap |
| title_fullStr | Preliminary Results on Irradiance Measurements from Lyra and Swap |
| title_full_unstemmed | Preliminary Results on Irradiance Measurements from Lyra and Swap |
| title_short | Preliminary Results on Irradiance Measurements from Lyra and Swap |
| title_sort | preliminary results on irradiance measurements from lyra and swap |
| url | http://dx.doi.org/10.1155/2012/623709 |
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