Abstract:
A VHF impulse radar system operating on the ground is a viable technique for mapping the near-surface geological structure and electrical properties of permafrost. A fixe...Show MoreMetadata
Abstract:
A VHF impulse radar system operating on the ground is a viable technique for mapping the near-surface geological structure and electrical properties of permafrost. A fixed antenna configuration transported over the surface yields a reconnaissance map of two-way travel times for subsurface reflectors. Wide-angle reflection and refraction (WARR) sounding determines propagation velocity versus depth when performed in layered areas. To obtain a WARR sounding, one measures travel time versus antenna separation. These techniques were field tested in the Tuktoyaktuk region of the Mackenzie River delta, N.W.T. Data recording was on a graphic display for initial field analysis and on analog magnetic tape for subsequent processing. Reconnaissance surveying has mapped structural features at various depths between 3 and 30 m. The electrical loss of the soils at a site limits the penetration depth. Clays and silts attenuate the radar signal more than sands and gravels. WARR soundings have determined dielectric constant versus depth in layered areas. While impulse radar is useful in delineating geological structure, core drilling is required to determine the geological composition.
Published in: Radio Science ( Volume: 11, Issue: 4, April 1976)
Geological Survey of Canada, Ottawa, Ontario, Canada K1A 0E8
Geological Survey of Canada, Ottawa, Ontario, Canada K1A 0E8
Geological Survey of Canada, Ottawa, Ontario, Canada K1A 0E8
Geological Survey of Canada, Ottawa, Ontario, Canada K1A 0E8