Geomagnetic induction study using the NetLander network of magnetometers

The NetLander mission will provide a unique opportunity to probe the intern al structure of Mars from continuous magnetic recordings at the surface of the planet. When the resistivity varies only with depth, and the externally originating variations are homogeneous at the scale of the studied area, t he resistivity distribution can be related to the ratio of the vertical mag netic field to the spatial gradients of the horizontal magnetic field. Assu ming the field at the surface of Mars behaves as a superposition of plane w aves, the spatial gradient determination is equivalent to wave vectors iden tification. We present a multi-point data analysis technique initially deve loped in the frame of Cluster, the future ESA multi-spacecraft mission. It allows to obtain optimum frequency-wave vector spectra estimation from simu ltaneous magnetic field recordings made at a subset of three NetLander stat ions. The analysis of synthetic data have made it possible to study the eff ects of experimental constraints for NetLander on the frequency-wave vector spectrum estimation. (C) 2000 Elsevier Science Ltd. All rights reserved.