Imaging of polar cap patches with a low-cost airglow camera: pilot observations in Svalbard, Norway
Abstract We evaluate the capability of a low-cost all-sky imager (ASI), which has been operative in Longyearbyen (78.1° N, 15.5° E), Norway, to detect 630.0 nm airglow signatures of polar cap patches. The ASI is composed of a small camera, with a charge-coupled device (CCD), manufactured by Watec Co...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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SpringerOpen
2019-11-01
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| Series: | Earth, Planets and Space |
| Subjects: | |
| Online Access: | http://link.springer.com/article/10.1186/s40623-019-1094-7 |
| _version_ | 1818455378844712960 |
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| author | Keisuke Hosokawa Yasunobu Ogawa Satoshi Taguchi |
| author_facet | Keisuke Hosokawa Yasunobu Ogawa Satoshi Taguchi |
| author_sort | Keisuke Hosokawa |
| collection | DOAJ |
| description | Abstract We evaluate the capability of a low-cost all-sky imager (ASI), which has been operative in Longyearbyen (78.1° N, 15.5° E), Norway, to detect 630.0 nm airglow signatures of polar cap patches. The ASI is composed of a small camera, with a charge-coupled device (CCD), manufactured by Watec Co. Ltd., a fish-eye lens, and an optical filter whose central wavelength is 632.0 nm and full-width half maximum (FWHM) is 10 nm. In Longyearbyen, another ASI equipped with a cooled electron-multiplying charge-coupled device (EMCCD) camera has been operative for observations of polar cap patches. We compare the images from the two systems and investigate the performance of the low-cost ASI. On the night of December 4, 2013, a series of polar cap patches were observed by the EMCCD ASI. The low-cost ASI also detected regions of enhanced 630.0 nm airglow passing through the fields-of-view. The quality of the raw images from the low-cost ASI obtained every 4 s were visibly much worse than that of the EMCCD ASI. However, an integration of 7–15 consecutive images made it possible to capture the temporal evolution and spatial structure of the patches, for example, their anti-sunward propagation and finger-like structures along the trailing edge. The estimated values of the absolute optical intensity from the low-cost ASI were found to be consistent with those from the EMCCD ASI, whereby the offset was < 100 R. This offset can be explained by the contribution of the background continuum emission to the low-cost ASI images, because the band width of the optical filter used for the low-cost ASI is ~ 3 times wider than that used for the EMCCD ASI. The results indicate that the airglow measurement with the low-cost ASI is feasible even for quantitative studies of F-region phenomena such as the dynamics of polar cap patches. |
| first_indexed | 2024-12-14T22:09:50Z |
| format | Article |
| id | doaj.art-4ef4073d387743dd9349a6f3e29a379b |
| institution | Directory Open Access Journal |
| issn | 1880-5981 |
| language | English |
| last_indexed | 2024-12-14T22:09:50Z |
| publishDate | 2019-11-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Earth, Planets and Space |
| spelling | doaj.art-4ef4073d387743dd9349a6f3e29a379b2022-12-21T22:45:46ZengSpringerOpenEarth, Planets and Space1880-59812019-11-0171111010.1186/s40623-019-1094-7Imaging of polar cap patches with a low-cost airglow camera: pilot observations in Svalbard, NorwayKeisuke Hosokawa0Yasunobu OgawaSatoshi Taguchi1University of Electro-CommunicationsGraduate School of Science, Kyoto UniversityAbstract We evaluate the capability of a low-cost all-sky imager (ASI), which has been operative in Longyearbyen (78.1° N, 15.5° E), Norway, to detect 630.0 nm airglow signatures of polar cap patches. The ASI is composed of a small camera, with a charge-coupled device (CCD), manufactured by Watec Co. Ltd., a fish-eye lens, and an optical filter whose central wavelength is 632.0 nm and full-width half maximum (FWHM) is 10 nm. In Longyearbyen, another ASI equipped with a cooled electron-multiplying charge-coupled device (EMCCD) camera has been operative for observations of polar cap patches. We compare the images from the two systems and investigate the performance of the low-cost ASI. On the night of December 4, 2013, a series of polar cap patches were observed by the EMCCD ASI. The low-cost ASI also detected regions of enhanced 630.0 nm airglow passing through the fields-of-view. The quality of the raw images from the low-cost ASI obtained every 4 s were visibly much worse than that of the EMCCD ASI. However, an integration of 7–15 consecutive images made it possible to capture the temporal evolution and spatial structure of the patches, for example, their anti-sunward propagation and finger-like structures along the trailing edge. The estimated values of the absolute optical intensity from the low-cost ASI were found to be consistent with those from the EMCCD ASI, whereby the offset was < 100 R. This offset can be explained by the contribution of the background continuum emission to the low-cost ASI images, because the band width of the optical filter used for the low-cost ASI is ~ 3 times wider than that used for the EMCCD ASI. The results indicate that the airglow measurement with the low-cost ASI is feasible even for quantitative studies of F-region phenomena such as the dynamics of polar cap patches.http://link.springer.com/article/10.1186/s40623-019-1094-7IonospherePolar cap patchesAirglowOptical observationsSatellite navigation |
| spellingShingle | Keisuke Hosokawa Yasunobu Ogawa Satoshi Taguchi Imaging of polar cap patches with a low-cost airglow camera: pilot observations in Svalbard, Norway Earth, Planets and Space Ionosphere Polar cap patches Airglow Optical observations Satellite navigation |
| title | Imaging of polar cap patches with a low-cost airglow camera: pilot observations in Svalbard, Norway |
| title_full | Imaging of polar cap patches with a low-cost airglow camera: pilot observations in Svalbard, Norway |
| title_fullStr | Imaging of polar cap patches with a low-cost airglow camera: pilot observations in Svalbard, Norway |
| title_full_unstemmed | Imaging of polar cap patches with a low-cost airglow camera: pilot observations in Svalbard, Norway |
| title_short | Imaging of polar cap patches with a low-cost airglow camera: pilot observations in Svalbard, Norway |
| title_sort | imaging of polar cap patches with a low cost airglow camera pilot observations in svalbard norway |
| topic | Ionosphere Polar cap patches Airglow Optical observations Satellite navigation |
| url | http://link.springer.com/article/10.1186/s40623-019-1094-7 |
| work_keys_str_mv | AT keisukehosokawa imagingofpolarcappatcheswithalowcostairglowcamerapilotobservationsinsvalbardnorway AT yasunobuogawa imagingofpolarcappatcheswithalowcostairglowcamerapilotobservationsinsvalbardnorway AT satoshitaguchi imagingofpolarcappatcheswithalowcostairglowcamerapilotobservationsinsvalbardnorway |