At 11:10 AM 1/13/2007, Ken Kinyon wrote:
>Is anyone aware of any studies done on the effect of ground snow on the RF
>reflectivity of the soil underneath the snow?
>It is not usual for the front range of Colorado to have significant
>snow on the
>ground for any significant length of time.
>However since two feet of snow fell shortly before Christmas, We have had at
>least another foot and most of it is still here although compacted
>significantly. It is my subjective observation that I an not receiving or
>transmitting as well since the snow fell. Everything looks normal
>with all the
>equipment. Antenna SWR and directivity seem unchanged. Is it
>possible that the
>snow is absorbing RF that would ordinarily reflect off the ground and combine
>with direct radiation, thereby changing the vertical radiation
>idea is that the snow is reflecting RF, raising the effective height of the
>ground (which I assume is some feet under the actual ground normally), thereby
>making my antenna perform as though it were closer to ground.
>Yes, cabin fever makes one ponder strange things. ;<)
>Thanks and 73,
I don't know much about snow properties at HF, but at Ku-band (13.402
GHz, to be specific), the dielectric properties change a great deal
with temperature and moisture content. Ice is not particularly lossy
or conductive. Water is very much so.
>Kenneth E. Kinyon
>34 Princeton Circle
>Longmont, CO 80503-2106
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