An investigation of hf data communication circuits at high latitudes.
The high latitude ionosphere forms a highly dynamic and disturbed medium which can severely degrade the performance of hf radio links. Characteristics of the signal which may be affected include signal strength, fading rate and the frequency range over which signals may propagate. Furthermore, large...
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Engineering
2015
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ftleicester:oai:lra.le.ac.uk:2381/34758 2023-05-15T15:35:28+02:00 An investigation of hf data communication circuits at high latitudes. Dhanda, Baljinder Singh. 2015-11-19T08:58:55Z http://hdl.handle.net/2381/34758 en eng Engineering University of Leicester http://hdl.handle.net/2381/34758 U071155 x753093218 Copyright © the author. All rights reserved. ProQuest Thesis Doctoral Ph.D. 2015 ftleicester 2019-03-22T20:20:56Z The high latitude ionosphere forms a highly dynamic and disturbed medium which can severely degrade the performance of hf radio links. Characteristics of the signal which may be affected include signal strength, fading rate and the frequency range over which signals may propagate. Furthermore, large Doppler frequency shifts and spreads may be imposed on the signal due to movements in the ionosphere near to the reflection point. To investigate these effects, signals from a transmitter located at Clyde River on Baffin Island in the Canadian North West Territories were received near Fairbanks, Alaska and at Alert, Elsmere Island. Doppler spread, signalling error rates and error distribution patterns occurring were measured during one month campaigns in summer 1988 and winter 1989. Several interesting features were observed: (a) Large Doppler spreads, often in excess of 10 Hz were frequently observed on the trans-auroral path and their occurrence was well correlated with the average position of the auroral oval relative to the path reflection points. (b) The bit error rate of low speed FSK signals was not influenced by the level of Doppler spreading observed. Error rate was well correlated with the received signal to noise ratio and was in good agreement with theory. Signal to noise ratio was well correlated with predicted variations in ionisation due to changes in solar zenith angle. (c) Distribution of errors were related to changes in Doppler spreading. Large Doppler spreads, were correlated with significantly shorter bursts of error was less than when Doppler spreading was small. However, there was no significant correlation with the length of guard space between errors. This work is of particular relevance to researchers developing high latitude prediction programs and those employing channel simulators to assess communication systems. Doctoral or Postdoctoral Thesis Baffin Island Baffin Alaska University of Leicester: Leicester Research Archive (LRA) Baffin Island Clyde River ENVELOPE(-70.451,-70.451,69.854,69.854) Fairbanks |
institution |
Open Polar |
collection |
University of Leicester: Leicester Research Archive (LRA) |
op_collection_id |
ftleicester |
language |
English |
description |
The high latitude ionosphere forms a highly dynamic and disturbed medium which can severely degrade the performance of hf radio links. Characteristics of the signal which may be affected include signal strength, fading rate and the frequency range over which signals may propagate. Furthermore, large Doppler frequency shifts and spreads may be imposed on the signal due to movements in the ionosphere near to the reflection point. To investigate these effects, signals from a transmitter located at Clyde River on Baffin Island in the Canadian North West Territories were received near Fairbanks, Alaska and at Alert, Elsmere Island. Doppler spread, signalling error rates and error distribution patterns occurring were measured during one month campaigns in summer 1988 and winter 1989. Several interesting features were observed: (a) Large Doppler spreads, often in excess of 10 Hz were frequently observed on the trans-auroral path and their occurrence was well correlated with the average position of the auroral oval relative to the path reflection points. (b) The bit error rate of low speed FSK signals was not influenced by the level of Doppler spreading observed. Error rate was well correlated with the received signal to noise ratio and was in good agreement with theory. Signal to noise ratio was well correlated with predicted variations in ionisation due to changes in solar zenith angle. (c) Distribution of errors were related to changes in Doppler spreading. Large Doppler spreads, were correlated with significantly shorter bursts of error was less than when Doppler spreading was small. However, there was no significant correlation with the length of guard space between errors. This work is of particular relevance to researchers developing high latitude prediction programs and those employing channel simulators to assess communication systems. |
format |
Doctoral or Postdoctoral Thesis |
author |
Dhanda, Baljinder Singh. |
spellingShingle |
Dhanda, Baljinder Singh. An investigation of hf data communication circuits at high latitudes. |
author_facet |
Dhanda, Baljinder Singh. |
author_sort |
Dhanda, Baljinder Singh. |
title |
An investigation of hf data communication circuits at high latitudes. |
title_short |
An investigation of hf data communication circuits at high latitudes. |
title_full |
An investigation of hf data communication circuits at high latitudes. |
title_fullStr |
An investigation of hf data communication circuits at high latitudes. |
title_full_unstemmed |
An investigation of hf data communication circuits at high latitudes. |
title_sort |
investigation of hf data communication circuits at high latitudes. |
publisher |
Engineering |
publishDate |
2015 |
url |
http://hdl.handle.net/2381/34758 |
long_lat |
ENVELOPE(-70.451,-70.451,69.854,69.854) |
geographic |
Baffin Island Clyde River Fairbanks |
geographic_facet |
Baffin Island Clyde River Fairbanks |
genre |
Baffin Island Baffin Alaska |
genre_facet |
Baffin Island Baffin Alaska |
op_source |
ProQuest |
op_relation |
http://hdl.handle.net/2381/34758 U071155 x753093218 |
op_rights |
Copyright © the author. All rights reserved. |
_version_ |
1766365800728363008 |