f PROUDLY PRESENTING MAISIE, A NEW AIRBORNE EM PLATFORM FOR POLAR RESEARCH

The polar oceans’ sea ice cover is an unconventional and challenging geophysical target to map. Current state of practice helicopter-electromagnetic (HEM) ice thickness mapping is limited to 1D interpretation due to common procedures and systems that are mainly sensitive to layered structures. We present a new generation Multi-sensor, Airborne Sea Ice Explorer (MAiSIE) to overcome these limitations. 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 500 Hz to 8 kHz, expressed as normalized secondary fields in x, y, and z direction, increases the accuracy of HEM derived pressure ridge geometry significantly.