Footprint Size of a Helicopter-Borne Electromagnetic Induction Sounding System Versus Antenna Altitude

• Main Authors: Kovacs, Austin, Holladay, J. S., Bergeron, Jr, Clyde J.
• Other Authors: COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH
• Format: Text
• Language: English
• Published: 1993
• Subjects: Snow; Ice and Permafrost; Acoustic Detection and Detectors; Electricity and Magnetism; *ELECTROMAGNETIC INDUCTION; *SEA ICE; *SOUNDING; DIAMETERS; MEASUREMENT; THICKNESS; ICE; MEASURING INSTRUMENTS; REMOTE DETECTION; ELECTRICAL MEASUREMENT; ANTENNAS; CONFIGURATIONS; HELICOPTERS; SURFACES; BATHYMETRY; REMOTE SENSING; HEM(HELICOPTER TOWED ELECTROMAGNETIC) INDUCTION; FOOTPRINTS; Ice; permafrost; Sea ice
• Online Access: http://www.dtic.mil/docs/citations/ADA270468; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA270468

Helicopter-towed electromagnetic induction sounding systems have recently been used for the remote measurement of sea-ice thickness and shallow sea bathymetry. An inherent aspect of this sensing technology is the large area, the footprint, over which an individual sounding is made. This report gives an overview of previous footprint size assessments and presents new footprint size estimates determined from sea ice survey data and analytical calculations. All footprint determinations were found to be in reasonable agreement. For a vertical coaxial coil antenna arrangement the apparent footprint diameter was found to be about 1.25 times the antenna height above the conductive surface, and for a horizontal coplanar coil configuration the ratio is about 3.75 times the antenna height. HEM footprint size, Ice, Remote sensing, HEM induction sounding, Remote measurement