Online reconstruction of drifting underwater ice topography: The 2D case

• Published in: Asian Journal of Control
• Main Authors: Jørgensen, Ulrik, Skjetne, Roger
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley Online Library 2015
• Subjects: VDP::Teknologi: 500::Marin teknologi: 580::Offshoreteknologi: 581; VDP::Technology: 500::Marine technology: 580::Offshore technology: 581; VDP::Teknologi: 500::Informasjons- og kommunikasjonsteknologi: 550::Teknisk kybernetikk: 553; VDP::Technology: 500::Information and communication technology: 550::Technical cybernetics: 553; Isforvaltning / Ice Management; Greenland; Ice Sheet
• Online Access: http://hdl.handle.net/11250/2357302; https://doi.org/10.1002/asjc.1088

An online estimation design for a drifting two dimensional ice topography is presented. Under the assumption that the topography can be accurately represented by a truncated Fourier series, and given a moving window of measurements along the topography, an observer design is proposed to estimate the parameters of the model. The chosen method ensures an online cutoff of higher wave numbers in the spectrum representing the topography such that sufficient data compression is achieved for transmitting the model parameters through a limited hydroacoustic communication channel. This allows online reconstruction of the underwater drifting ice topography at a remote operation center. The observer is shown to be uniformly globally exponentially stable under a persistency of excitation condition. For comparison, a design based on B-spline basis functions is also presented. The effectiveness of the estimation algorithm is verified on a set of real ice draft measurements taken from the underside of an ice sheet off the coast of Greenland. © 2015 The Authors Asian Journal of Control published by Chinese Automatic Control Society and Wiley Publishing Asia Pty Ltd. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.