Scottish Links
description
Transcript of Scottish Links
FSTG 29/4/2002 1
Scottish Links
Kevin Paulson
Rutherford Appleton Laboratory,
Chilton Didcot, Oxfordshire, OX11 0QX
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Scottish Links Experiment
► Investigate the effects of sleet and snow on commercial links.
► Monitor link attenuations at several hubs around Dundee.
► Observe high attenuation events with St Andrews radar.
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The Links
Taybridge Links
Craigowl Links
LinkNumber
Lengthkm
FrequencyGHz
Polarity RainFade0.01%
Comments
0 3.16 22 V 6.0 dB1 7.37 22 V 12.3 dB2 3.46 22 V 6.5 dB Uncalibrated3 12.83 22 V 18.3 dB Uncalibrated4 12.83 13 V 6.8 dB5 4.06 25.6 V 9.7 dB
LinkNumber
Lengthkm
FrequencyGHz
Polarity RainFade0.01%
Comments
0 26.55 13 V 10.3 dB Erratic1 12.7 22 V 18.2 dB Uncalibrated2 27.85 13 V 10.5 dB3 13.03 13 V 6.8 dB4 20.88 13 V 9.1 dB5 12.7 13 V 6.7 dB6 2.04 22 V 3.9 dB7 10.37 13 V 5.8 dB
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February 7 2002
Overcast and cold with temp. rising from 3 to 6 degrees by afternoon.
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Taybridge Results 7/2/02
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Craigowl Results 7/2/02
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March 10 2002
Temperatures between -2 and 1 degree with sleet and snow.
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Taybridge Results 10/3/02
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Craigowl Results 10/3/02
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Conclusions
► 8 events in the period 1/1/02-21/3/02 where one or more links experience attenuation >A0.01% due to sleet.
► Craigowl experiences more sleet events than Taybridge (and both considerably more than Winchester/Thorne Hill)
► Many of the extreme attenuation events last much longer than predicted by the RAL fade duration model.
► Sometimes extreme attenuation is restricted to a small number of links indicating spatial inhomogeneity in sleet.
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Attenuation Exceedances Taybridge