Fast onboard detection of ice drift changes under stationkeeping in ice

Abstract

Early detection of ice drift changes is essential for safe stationkeeping in ice-infested waters. This paper presents a conceptual system allowing onboard detection of ice drift changes in managed and unmanaged ice using distributed accelerometers installed in the hull of a stationkeeping vessel. With methods from statistical signal processing, specifically probability of exceedance analysis, a relation between the measured signals' entropy and the location along the hull where the ice action occurs is found. With field data from a stationkeeping operation in the Bay of Bothnia this relation is validated. The main contribution of this paper is a concept for ice drift estimation which only requires distributed vibration measurements along the hull and the ship's heading information.