1. Inter‐university Ctr. on, Integrated Systems for the Marine EnvironmentResearch Center “E.Piaggio”, Dept. of Energy and Systems EngineeringUniversity of Pisa Pisa 56127 Italy
2. Inter‐university Ctr. on, Integrated Systems for the Marine EnvironmentResearch Center “E.Piaggio”, Dept. of Information Engineering, University of Pisa Pisa 56127 Italy
3. Institute of Informatics and TelematicsNational Research Council, Via Giuseppe Moruzzi Pisa 56124 Italy