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FSTG 29/4/2002 1 Scottish Links Kevin Paulson Rutherford Appleton Laboratory, Chilton Didcot, Oxfordshire, OX11 0QX

Scottish Links

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Scottish Links. Kevin Paulson Rutherford Appleton Laboratory, Chilton Didcot, Oxfordshire, OX11 0QX. Scottish Links Experiment. Investigate the effects of sleet and snow on commercial links. Monitor link attenuations at several hubs around Dundee. - PowerPoint PPT Presentation

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Page 1: Scottish Links

FSTG 29/4/2002 1

Scottish Links

Kevin Paulson

Rutherford Appleton Laboratory,

Chilton Didcot, Oxfordshire, OX11 0QX

Page 2: Scottish Links

FSTG 29/4/2002 2

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.

Page 3: Scottish Links

FSTG 29/4/2002 3

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

Page 4: Scottish Links

FSTG 29/4/2002 4

February 7 2002

Overcast and cold with temp. rising from 3 to 6 degrees by afternoon.

Page 5: Scottish Links

FSTG 29/4/2002 5

Taybridge Results 7/2/02

Page 6: Scottish Links

FSTG 29/4/2002 6

Craigowl Results 7/2/02

Page 7: Scottish Links

FSTG 29/4/2002 7

March 10 2002

Temperatures between -2 and 1 degree with sleet and snow.

Page 8: Scottish Links

FSTG 29/4/2002 8

Taybridge Results 10/3/02

Page 9: Scottish Links

FSTG 29/4/2002 9

Craigowl Results 10/3/02

Page 10: Scottish Links

FSTG 29/4/2002 10

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.

Page 11: Scottish Links

FSTG 29/4/2002 11

Attenuation Exceedances Taybridge