A number of GPS augmentation systems have recently been developed for different applications in various regions. The manufacturers of these commercial services claim decimeter or near-decimeter level (1σ) horizontal positioning precision. These systems provide different types of correction and integrity signals to users via satellite links. Three services were studied: the NavCom Technology, In...

A large number of genera in the tropical fish family Characidae are incertae sedis. Cytogenetic analysis was made of four of these species: Astyanax eigenmanniorum, Deuterodon stigmaturus, Hyphessobrycon luetkenii, and H. anisitsi, collected from various hydrographic basins: hydrographic system from Laguna dos Patos/RS, Tramandaí basin/RS and Tibagi River basin/PR. The first two species we...

Experimental observations of acoustic propagation through a Soliton Wave Packet (SWP) show an abnormally large attenuation over some frequencies, that was found to be significantly time dependent and anisotropic. Nevertheless, by remarking the problem of signal attenuation, the approach used in most of the studies can be considered as ”static” since no additional effects were taken into account...

Monthly circulation of the South Atlantic Bight is diagnosed using a 3-D, shallow water, finite element model forced with monthly wind stress and hydrographic climatology. Temperature and salinity observations from the period 1950-99 are objectively interpolated onto the model domain, and Comprehensive Ocean-Atmosphere Data Set (COADS) wind velocities from 1975-1999 are used to prescribe the mo...

Multi-path interference due to boundary reflection in shallow water acoustic communication poses a major obstacle to reliable and high-speed underwater communication system. In this study, initially 3D variations of field data such as sound speed, temperature and salinity in horizontal transects of the Strait of Hormuz were analyzed using the ROPME data. Later, data on typical sound speed ...

The main part of the thesis is five separate research papers published in or submitted to leading journals in the field of computer vision and pattern recognition. In addition, a data capture system for hydrographic maps has been designed and implemented. It places the results of the thesis papers in context and demonstrate their importance. The five thesis papers are [1] Øivind Due Trier and T...

On 30 October 2020, a strong earthquake of magnitude 7.0 occurred north Samos Island at the Eastern Aegean Sea, whose mechanism corresponds to an E-W normal fault dipping north. During aftershock period in December hydrographic survey off northern coastal margin was conducted onboard R/V NAFTILOS. The result detailed bathymetric map with 15 m grid interval and 50 isobaths morphological slope ma...