• A brute-force spectral approach for wave estimation using measured vessel motions 

      Nielsen, Ulrik Dam; Brodtkorb, Astrid H.; Sørensen, Asgeir Johan (Journal article; Peer reviewed, 2018)
      The article introduces a spectral procedure for sea state estimation based on measurements of motion responses of a ship in a short-crested seaway. The procedure relies fundamentally on the wave buoy analogy, but the wave ...
    • Bayesian Estimation of Non-Stationary Ship Response Spectra 

      Møgster, Christian (Master thesis, 2015)
      The main topic of this master thesis is to obtain spectral information of non-stationary ship responses, with the motive of facilitating improvement of sea state estimation methods, that are using the wave buoy analogy. ...
    • Evaluation of Shipboard Wave Estimation Techniques Through Model-scale Experiments 

      Nielsen, Ulrik Dam; Galeazzi, Roberto; Brodtkorb, Astrid H. (Chapter, 2016)
      The paper continues a study on the wave buoy analogy that uses shipboard measurements to estimate sea states. In the present study, the wave buoy analogy is formulated directly in the time domain and relies only partly on ...
    • Hybrid Control of Marine Vessels: Dynamic Positioning in Varying Conditions 

      Brodtkorb, Astrid H. (Doctoral theses at NTNU;2017:351, Doctoral thesis, 2017)
      The next generation marine control systems will, as a step towards increased autonomy, have more automatic functionality in order to cope with a set of complex operations in unknown and varying environments, while maintaining ...
    • Online wave estimation using vessel motion measurements 

      Brodtkorb, Astrid H.; Nielsen, Ulrik Dam; Sørensen, Asgeir Johan (Journal article; Peer reviewed, 2018)
      In this paper, a computationally efficient online sea state estimation algorithm is proposed for estimation of the onsite sea state. The algorithm finds the wave spectrum estimate from motion measurements in heave, roll ...
    • Response predictions using the observed autocorrelation function 

      Nielsen, Ulrik Dam; Brodtkorb, Astrid H.; Jensen, Jørgen Juncher (Journal article; Peer reviewed, 2018)
      This article studies a procedure that facilitates short-time, deterministic predictions of the waveinduced motion of a marine vessel, where it is understood that the future motion of the vessel is calculated ahead of time. ...
    • Sea state estimation using model-scale DP measurements 

      Brodtkorb, Astrid H.; Nielsen, Ulrik Dam; Sørensen, Asgeir Johan (Chapter, 2015)
      Complex marine operations are moving further from shore, into deeper waters, and harsher environments. The operating hours of a vessel are weather dependent, and good knowledge of the prevailing weather conditions may ...
    • Sea state estimation using multiple ships simultaneously as sailing wave buoys 

      Nielsen, Ulrik Dam; Brodtkorb, Astrid H.; Sørensen, Asgeir Johan (Journal article; Peer reviewed, 2019)
      The article presents initial ideas towards a network-based approach for sea state estimation used for marine operations and other maritime applications. In principle, all available means, ranging from in situ buoys, fleet ...
    • Sea state estimation using vessel response in dynamic positioning 

      Brodtkorb, Astrid H.; Nielsen, Ulrik Dam; Sørensen, Asgeir Johan (Journal article; Peer reviewed, 2018)
      This paper presents a novel method for estimating the sea state parameters based on the heave, roll and pitch response of a vessel conducting station keeping automatically by a dynamic positioning (DP) system, i.e., without ...
    • Ship motion-based wave estimation using a spectral residual-calculation 

      Nielsen, Ulrik Dam; Brodtkorb, Astrid H. (Chapter, 2018)
      This paper presents a study focused on a newly developed procedure for wave spectrum estimation using wave-induced motion recordings from a ship. The particular procedure stands out from other existing, similar ship ...