Electromagnetic Induction Remote Sensing of Sea Ice Thickness. Phase 1

This report documents an investigation of the utility of electromagnetic (EM) induction as a technique for measuring sea ice thickness. A computer code was used to calculate the theoretical response of an existing EM induction geophysical tool, the Geonics Ltd. EM-31D, to sea ice thickness. The code...

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Bibliographic Details
Main Author: Echert, D. C.
Other Authors: FLOW RESEARCH CO KENT WA TECHNOLOGY DIV
Format: Text
Language:English
Published: 1986
Subjects:
Snow
Ice and Permafrost
Electrical and Electronic Equipment
Computer Programming and Software
Test Facilities
Equipment and Methods
*COMPUTER PROGRAMS
*SEA ICE
*INDUCTION SYSTEMS
*INSTRUMENTATION
*REMOTE DETECTORS
*ELECTROMAGNETIC INDUCTION
*PHYSICAL PROPERTIES
*CONDUCTIVITY
*COILS
*THICKNESS
*MEASUREMENT
*BUOYS
ORIENTATION(DIRECTION)
TEST AND EVALUATION
DEPTH
GEOPHYSICS
ICE
VERTICAL ORIENTATION
RESPONSE
ELECTROMAGNETIC RADIATION
CONFIGURATIONS
WATER
OCEANS
MODIFICATION
TOOLS
HORIZONTAL ORIENTATION
REAL TIME
AIR DROP OPERATIONS
HEIGHT
SEA WATER
OUTPUT
PLANAR STRUCTURES
ACCURACY
Ice
permafrost
Sea ice
Online Access:http://www.dtic.mil/docs/citations/ADA210281
http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA210281
Description
Summary:This report documents an investigation of the utility of electromagnetic (EM) induction as a technique for measuring sea ice thickness. A computer code was used to calculate the theoretical response of an existing EM induction geophysical tool, the Geonics Ltd. EM-31D, to sea ice thickness. The code also was used to evaluate the expected effect on the thickness measurements of ice conductivity, seawater conductivity, instrument height, and water depth. The instrument was taken to the Artic Ocean to test its actual response to ice thickness, including the effect of coils orientation, and instrument height. The measurements made by the instrument generally corresponded well with theory. Correspondence for the vertical coplanar coils configuration was better than for horizontal coils configuration. For the ice thickness tested, 0.10, 0.85 and 1. 68 m, the instrument output for vertical coils deviated from physical measurements by an average of 0.06 meters. Even greater accuracy would be possible if on-ice calibration procedures were developed. It is concluded that EM induction offers a practical and rapid method of measuring sea ice thickness. Modifications to the instrument to allow real time ice thickness and water conductivity readouts are described. The application of this technology to air-droppable buoys is discussed.

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