Umberto Severino - Academia.edu (original) (raw)
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Papers by Umberto Severino
Lecture notes in networks and systems, 2023
Water
Underwater photogrammetry provides a means of generating high-resolution products such as dense p... more Underwater photogrammetry provides a means of generating high-resolution products such as dense point clouds, 3D models, and orthomosaics with centimetric scale resolutions. Underwater photogrammetric models can be used to monitor the growth and expansion of benthic communities, including the assessment of the conservation status of seagrass beds and their change over time (time lapse micro-bathymetry) with OBIA classifications (Object-Based Image Analysis). However, one of the most complex aspects of underwater photogrammetry is the accuracy of the 3D models for both the horizontal and vertical components used to estimate the surfaces and volumes of biomass. In this study, a photogrammetry-based micro-bathymetry approach was applied to monitor Posidonia oceanica restoration actions. A procedure for rectifying both the horizontal and vertical elevation data was developed using soundings from high-resolution multibeam bathymetry. Furthermore, a 3D trilateration technique was also tes...
Lecture Notes in Mechanical Engineering, 2021
Lecture Notes in Mechanical Engineering
OCEANS 2019 - Marseille, 2019
In underwater localization several sources of error may impact in different ways the final estima... more In underwater localization several sources of error may impact in different ways the final estimation of the position. This applies to the Long Baseline (LBL), the Short Baseline (SBL) and the Ultra-Short Baseline (USBL) localization systems. Through simulations and statistical analysis, it is possible to identify and experimentally characterize such sources of error. It could be also investigated how much these sources of error influence the estimation results of an Extended Kalman Filter (EKF). This paper presents the results of experiments designed in a virtual environment, useful to represent real localization systems. Specifically, the system used for the simulation is constituted by a surface platform equipped with four acoustic transducers used for the localization of an underwater target.
Sensors
In underwater localization systems several sources of error may impact in different ways the accu... more In underwater localization systems several sources of error may impact in different ways the accuracy of the final position estimates. Through simulations and statistical analysis it is possible to identify and characterize such sources of error and their relative importance. This is especially of use when an accurate localization system has to be designed within required accuracy prescriptions. This approach allows one to also investigate how much these sources of error influence the final position estimates achieved by an Extended Kalman Filter (EKF). This paper presents the results of experiments designed in a virtual environment used to simulate real acoustic underwater localization systems. The paper intends to analyze the main parameters that significantly influence the position estimates achieved by a Short Baseline (SBL) system. Specifically, the results of this analysis are presented for a proprietary localization system constituted by a surface platform equipped with four ...
Lecture notes in networks and systems, 2023
Water
Underwater photogrammetry provides a means of generating high-resolution products such as dense p... more Underwater photogrammetry provides a means of generating high-resolution products such as dense point clouds, 3D models, and orthomosaics with centimetric scale resolutions. Underwater photogrammetric models can be used to monitor the growth and expansion of benthic communities, including the assessment of the conservation status of seagrass beds and their change over time (time lapse micro-bathymetry) with OBIA classifications (Object-Based Image Analysis). However, one of the most complex aspects of underwater photogrammetry is the accuracy of the 3D models for both the horizontal and vertical components used to estimate the surfaces and volumes of biomass. In this study, a photogrammetry-based micro-bathymetry approach was applied to monitor Posidonia oceanica restoration actions. A procedure for rectifying both the horizontal and vertical elevation data was developed using soundings from high-resolution multibeam bathymetry. Furthermore, a 3D trilateration technique was also tes...
Lecture Notes in Mechanical Engineering, 2021
Lecture Notes in Mechanical Engineering
OCEANS 2019 - Marseille, 2019
In underwater localization several sources of error may impact in different ways the final estima... more In underwater localization several sources of error may impact in different ways the final estimation of the position. This applies to the Long Baseline (LBL), the Short Baseline (SBL) and the Ultra-Short Baseline (USBL) localization systems. Through simulations and statistical analysis, it is possible to identify and experimentally characterize such sources of error. It could be also investigated how much these sources of error influence the estimation results of an Extended Kalman Filter (EKF). This paper presents the results of experiments designed in a virtual environment, useful to represent real localization systems. Specifically, the system used for the simulation is constituted by a surface platform equipped with four acoustic transducers used for the localization of an underwater target.
Sensors
In underwater localization systems several sources of error may impact in different ways the accu... more In underwater localization systems several sources of error may impact in different ways the accuracy of the final position estimates. Through simulations and statistical analysis it is possible to identify and characterize such sources of error and their relative importance. This is especially of use when an accurate localization system has to be designed within required accuracy prescriptions. This approach allows one to also investigate how much these sources of error influence the final position estimates achieved by an Extended Kalman Filter (EKF). This paper presents the results of experiments designed in a virtual environment used to simulate real acoustic underwater localization systems. The paper intends to analyze the main parameters that significantly influence the position estimates achieved by a Short Baseline (SBL) system. Specifically, the results of this analysis are presented for a proprietary localization system constituted by a surface platform equipped with four ...