Resumo: O Instituto Hidrográfico (IH) tem a capacidade através de diferentes equipamentos e meios técnicos de detetar e localizar objetos afundados, com recurso a técnicas de sonar lateral, multifeixe, magnetometria, auxiliados com... more
Resumo: O Instituto Hidrográfico (IH) tem a capacidade através de diferentes equipamentos e meios técnicos de detetar e localizar objetos afundados, com recurso a técnicas de sonar lateral, multifeixe, magnetometria, auxiliados com Veículos Operados Remotamente (ROV). Estas técnicas permitem reunir informação que poderá ser utilizada no apoio a atividades militar, arqueológica e para fins comerciais (prestações de serviço). Pretendemos realizar um enquadramento histórico e identificar os equipamentos utilizadas na deteção, localização e inspeção dos destroços do caça minas "Roberto Ivens".
This paper presents an overview of the test campaign performed with aim to validate the concept and technology solution proposed for a Digital Beam Forming based mul tisateliite tracking antenna system capable of receiving distress... more
This paper presents an overview of the test campaign performed with aim to validate the concept and technology solution proposed for a Digital Beam Forming based mul tisateliite tracking antenna system capable of receiving distress signals from MEO satellites for SAR (Search and Rescue) applications. Possibly, next ge neration of MEOLUTs (Medium Earth Orbit Local User Terminal) mi ght be based on a spherical array system employing geodesic dome approximation based on dodecahedron shape. In the frame of an ESA Contract entitled "Basic Active Array Module for MEOLUT application" an engineering model of the basic antenna triangle has been designed, ma nufactured and tested.
Multibeam satellite networks in Ka band have been designed to accommodate the increasing traffic demands expected in the future. However, these systems are spectrum limited due to the current spectrum allocation policies. This literature... more
Multibeam satellite networks in Ka band have been designed to accommodate the increasing traffic demands expected in the future. However, these systems are spectrum limited due to the current spectrum allocation policies. This literature review presentation investigates the potential of applying cognitive radio techniques in satellite communications (SatCom) in order to increase the spectrum opportunities for future generations of satellite networks without interfering with the operation of incumbent services. These extra spectrum opportunities can potentially amount to 2.4 GHz of bandwidth in the downlink and 2 GHz of bandwidth in the uplink for high density fixed satellite services (HDFSS).
This paper presents an overview of the test campaign performed with aim to validate the concept and technology solution proposed for a Digital Beam Forming based mul tisateliite tracking antenna system capable of receiving distress... more
This paper presents an overview of the test campaign performed with aim to validate the concept and technology solution proposed for a Digital Beam Forming based mul tisateliite tracking antenna system capable of receiving distress signals from MEO satellites for SAR (Search and Rescue) applications. Possibly, next ge neration of MEOLUTs (Medium Earth Orbit Local User Terminal) mi ght be based on a spherical array system employing geodesic dome approximation based on dodecahedron shape. In the frame of an ESA Contract entitled "Basic Active Array Module for MEOLUT application" an engineering model of the basic antenna triangle has been designed, ma nufactured and tested.
