Impulse radar experiments on permafrost near Tuktoyaktuk, Northwest Territories

Abstract

Field trials with a VHF impulse radar have been undertaken in the Tuktoyaktuk, N.W.T. area during the summer of 1973 and the spring seasons of 1974 and 1975. The radar transmits a wavelet with a centre frequency of 110 MHz and a pulse duration of 18 ns. Separate transmitter and receiver antennas were used.Preliminary interpretation of the data obtained at the Involuted Hill test site indicates that ice/sand interfaces were detected to ranges greater than 30 m. In icy sand, ice lenses separated by 3 m were resolved. Clay-till/ice interfaces were not detected at ranges greater than about 3 m. At other sites near the village of Tuktoyaktuk, sand/clay-till interfaces were detected at ranges greater than 5 m.Wide angle reflection and refraction sounding yields estimates of reflector depths and propagation velocities. Radar has proven useful in delineating geologic structure, but bore-hole control is required for identification of the geological composition of the structure.