Developments in frequency domain AEM; tackling drift and noise with a multicomponent, ferrite-core, receiver tipplet

• Main Authors: Pfaffhuber, A. A., Kvistedal, Yme, Hendricks, Stefan, Lied, Erik, Hunkeler, Priska
• Format: Book
• Language: unknown
• Published: ASEG 2013
• Subjects: Sea ice
• Online Access: https://epic.awi.de/id/eprint/34079/; https://epic.awi.de/id/eprint/34079/1/ASEG2013ab175.pdf; http://www.publish.csiro.au/paper/ASEG2013ab175.htm; https://hdl.handle.net/10013/epic.42355; https://hdl.handle.net/10013/epic.42355.d001

The polar oceans' sea ice cover is a 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. With MAiSIE we present a new EM concept based on one multi frequency transmitter loop and a three component receiver coil triplet without bucking The small weight frees additional payload to include a line scanner (lidar) and high accuracy INS/dGPS. The 3D surface topography from the scanner with the EM data at from 500 Hz to 8 kHz, in x, y, and z direction, will increase the accuracy of HEM derived pressure ridge geometry significantly. Experience from two field campaigns shows the proof-of-concept with acceptable sensor drift and receiver sensitivity. The preliminary 20 ppm noise level @ 4.1 kHz is sufficient to map level ice thickness with 10 cm precision for sensor altitudes below 13 m.