Real-time 3D Reconstruction of Underwater Sea-ice Topography by Observations from a Mobile Robot in the Arctic

In this paper we present an online estimation design for a drifting three dimensional ice topography. Representing the topography by a 2D truncated Fourier series model based on a set of nodes distributed over the area of interest, an observer is proposed to estimate the unknown coefficients of the model. The measurements are assumed provided by an underwater robot equipped with an upward-looking multi-beam echo sounder or similar. An observer is defined for each node to filter the ice draft measurements and handle the on-off switching when the underwater mobile sensor moves in and out of range. The effectiveness of the estimation algorithm is simulated based on an extensive data set with a highly varying seabed topography, emulating in our case a typical ice topography.