A continuous profile of sea ice and freshwater ice thickness by impulse radar

Abstract

For several years. Geophysical Survey Systems, Inc has been using an impulse radar system as a shallow subsurface exploration tool for engineering applications. Recently this system has been applied to the measurement of ice thicknesses both on sea-water and fresh-water ice. In the course of a feasibility study performed in December 1972, thebasic operating parameters and limitations of the tool when operated on ice were determined. Following the feasibility study, operational surveys were performed totalling approximately 11 crew-months and covering in excess of 1 500 km of survey route at several locations in the Canadian Arctic. The technique is known as Electromagnetic Subsurface Profiling (ESP), and it can be considered the electromagnetic equivalent of the single-trace acoustic profiling methods used for marine subbottom profiling. In practice, ice-thickness profiling is done by towing a sled-mounted antenna behind a tracked vehicle containing the impulse system (Fig 1). Real-time profile data are displayed graphically on a strip-chart recorder. The data may also be recorded on magnetic tape for later processing and playback.