Omega Navigation in the Shadow of Antarctica
1. INTRODUCTION. Very-low-frequency radio waves were used to implement the Omega navigation system because of their low attenuation (2–4 dB/1000 km) when propagating globally in the waveguide formed between the Earth and the ionosphere. However, it became apparent in the early seventies, throughout...
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Cambridge University Press (CUP)
1989
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crcambridgeupr:10.1017/s0373463300014442 2024-03-03T08:38:10+00:00 Omega Navigation in the Shadow of Antarctica Barr, R. Young, K. B. 1989 http://dx.doi.org/10.1017/s0373463300014442 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0373463300014442 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Journal of Navigation volume 42, issue 2, page 236-247 ISSN 0373-4633 1469-7785 Ocean Engineering Oceanography journal-article 1989 crcambridgeupr https://doi.org/10.1017/s0373463300014442 2024-02-08T08:39:04Z 1. INTRODUCTION. Very-low-frequency radio waves were used to implement the Omega navigation system because of their low attenuation (2–4 dB/1000 km) when propagating globally in the waveguide formed between the Earth and the ionosphere. However, it became apparent in the early seventies, throughout the period when the majority of the stations of the Omega network were commissioned, that VLF signals propagating over permafrost or glacial ice could suffer anomalously large attenuations, of greater than 20 dB/1000 km, especially during the daytime. In the Northern Hemisphere problems have arisen with the heavy attenuation of Omega signals propagating over the Greenland ice sheet. In particular a very bad region for Omega coverage occurs around Winnipeg in Canada (the ‘Winnipeg Hole’). In this area Omega North Dakota suffers from ‘near field’ effects, Omega Liberia is contaminated by trans-equatorial modal effects and Omega Norway is removed by the attenuation of its signals when crossing the Greenland ice-cap. There have even been discussions on the feasibility of constructing extra VLF transmitters in Canada to alleviate this problem. Article in Journal/Newspaper Antarc* Antarctica Greenland Ice Ice cap Ice Sheet permafrost Cambridge University Press Canada Greenland Norway Journal of Navigation 42 2 236 247 |
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Open Polar |
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Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Ocean Engineering Oceanography |
spellingShingle |
Ocean Engineering Oceanography Barr, R. Young, K. B. Omega Navigation in the Shadow of Antarctica |
topic_facet |
Ocean Engineering Oceanography |
description |
1. INTRODUCTION. Very-low-frequency radio waves were used to implement the Omega navigation system because of their low attenuation (2–4 dB/1000 km) when propagating globally in the waveguide formed between the Earth and the ionosphere. However, it became apparent in the early seventies, throughout the period when the majority of the stations of the Omega network were commissioned, that VLF signals propagating over permafrost or glacial ice could suffer anomalously large attenuations, of greater than 20 dB/1000 km, especially during the daytime. In the Northern Hemisphere problems have arisen with the heavy attenuation of Omega signals propagating over the Greenland ice sheet. In particular a very bad region for Omega coverage occurs around Winnipeg in Canada (the ‘Winnipeg Hole’). In this area Omega North Dakota suffers from ‘near field’ effects, Omega Liberia is contaminated by trans-equatorial modal effects and Omega Norway is removed by the attenuation of its signals when crossing the Greenland ice-cap. There have even been discussions on the feasibility of constructing extra VLF transmitters in Canada to alleviate this problem. |
format |
Article in Journal/Newspaper |
author |
Barr, R. Young, K. B. |
author_facet |
Barr, R. Young, K. B. |
author_sort |
Barr, R. |
title |
Omega Navigation in the Shadow of Antarctica |
title_short |
Omega Navigation in the Shadow of Antarctica |
title_full |
Omega Navigation in the Shadow of Antarctica |
title_fullStr |
Omega Navigation in the Shadow of Antarctica |
title_full_unstemmed |
Omega Navigation in the Shadow of Antarctica |
title_sort |
omega navigation in the shadow of antarctica |
publisher |
Cambridge University Press (CUP) |
publishDate |
1989 |
url |
http://dx.doi.org/10.1017/s0373463300014442 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0373463300014442 |
geographic |
Canada Greenland Norway |
geographic_facet |
Canada Greenland Norway |
genre |
Antarc* Antarctica Greenland Ice Ice cap Ice Sheet permafrost |
genre_facet |
Antarc* Antarctica Greenland Ice Ice cap Ice Sheet permafrost |
op_source |
Journal of Navigation volume 42, issue 2, page 236-247 ISSN 0373-4633 1469-7785 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s0373463300014442 |
container_title |
Journal of Navigation |
container_volume |
42 |
container_issue |
2 |
container_start_page |
236 |
op_container_end_page |
247 |
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1792505180058550272 |