| 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.
During the my time in the Antarctic 1974 through 1976 I observed some ice
depth radar work. This involved flying for hours at 50 feet above the
snow surface, determined by radar altimeter and probing the rock bottom
with 70MHz pulses, transmitted and received by dipole antennas mounted
under the wings of a DHC Twin Otter. The only time I've flown with
reverse pitch to maintain a high sink rate without exceeding the max
forward speed determined by the experiment.
As far as I am aware snow and ice is transparent to HF. It is known that
one base on the Antarctic mainland had a rhombic that slowly vanished
under the snow surface without ill effect apart from being eventually
damaged by differential ice movement. I once laid out a "V" on the
surface near our snow ski-way which was on about 600 feet thick snow/ice.
It seemed to work OK but I didn't hang around too long. The VFO knob of
the FT-101 I was using was most difficult to turn and the inverter
transistors of the DC PSU were so cold they didn't want to start up until
after a few ON/OFF cycles.
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