Progressing from 1D to 2-3D near surface airborne electromagnetic mapping: Development of MAiSIE, a Multi-Sensor, Airborne Sea Ice Explorer

• Published in: GEOPHYSICS
• Main Authors: Pfaffhuber, Andreas, Hendricks, Stefan, Kvistedal, Yme
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: SOC EXPLORATION GEOPHYSICISTS 2012
• Subjects: Sea ice
• Online Access: https://epic.awi.de/id/eprint/25161/; https://epic.awi.de/id/eprint/25161/1/Geopyhsics_MAiSIE.pdf; https://hdl.handle.net/10013/epic.40501; https://hdl.handle.net/10013/epic.40501.d001

The polar oceans’ sea ice cover is an unconventional and challenging geophysical target to map. Current state of ractice helicopter-electromagnetic (HEM) ice thickness apping is limited to 1D interpretation due to common rocedures and systems that are mainly sensitive to layered tructures. We present a new generation Multi-sensor, irborne Sea Ice Explorer (MAiSIE) to overcome these imitations. As the actual sea ice structure is 3D and in parts heterogeneous, errors up to 50% are observed due to the common 1D approximation. By virtue of 3D finite element modeling, we find that more than one frequency is needed, ideally in the range 1 – 5 kHz, to improve thickness estimates of grounded pressure ridges, a common 3D sea ice structure. With MAiSIE we present a new electromagnetic (EM) concept based on one multi frequency transmitter loop and a three component receiver coil triplet, with active digital bucking (no bucking coil). The comparably small weight of the EM components frees enough additional payload to include three laser devices including a line scanner and high accuracy INS/dGPS. Integrating the high resolution 3D ice surface topography from the laser scanner with the EM data at frequencies from 600 Hz to 10 kHz, expressed as normalized secondary fields in x, y, and z direction, increases the accuracy of HEM derived pressure ridge geometry significantly.