Mapeamento com Sonar Usando Grade de Ocupação baseado em Modelagem Probabilística

In this work, we propose a probabilistic mapping method with the mapped environment represented through a modified occupancy grid. The main idea of the proposed method is to allow a mobile robot to construct in a systematic and incremental way the geometry of the underlying space, obtaining at the end a complete environment map. As a consequence, the robot can move in the environment in a safe way, based on a confidence value of data obtained from its perceptive system. The map is represented in a coherent way, according to its sensory data, being these noisy or not, that comes from exterior and proprioceptive sensors of the robot. Characteristic noise incorporated in the data from these sensors are treated by probabilistic modeling in such a way that their effects can be visible in the final result of the mapping process. The results of performed experiments indicate the viability of the methodology and its applicability in the area of autonomous mobile robotics, thus being an contribution to the field

Impactos de atividades de exploração de petróleo e gás natural sobre a comunicação acústica de Mysticeti (ordem Cetacea): uma revisão

Acoustic communication is essential in mammals and has three main functions: acquisition of information about the environment, intraspecific communication and detection of predators and prey. Studies indicate that the introduction of sounds produced by anthropogenic activities such as military exercises, use of sonar and activities related to the extraction of oil and natural gas can cause interference in cetacean communication. Recently, the discovery of pre-salt tends to increase these activities. After a decade since the launch date of IBAMA`s licensing and before the imminent increase in exploration activities in Brazil, it is essential to conduct studies to monitor closely the impact of this type of activity on the marine ecosystem. Thus, this study aims to identify potential impacts that the process of oil and natural gas exploration and production might have on the communication of baleen whales. Data from literature on bioacoustics and ecology of these animals were linked with technical-scientific data regarding this type of activity. 310 documents related to the topic were analyzed. Among them only 81 documents are of academic origin, and the others mostly action plans and reports from government agencies. 80% of the documents do not have any species as a focus, and in the remaining 20%, 17% were focused on the Greenland Whale (Balaena mysticetus) and 22% on the gray whale (Eschrichtius robustus). The main impacts identified in this study were the increased frequency and amplitude of vocalization, reduction or cessation of more elaborate songs and masking problems

Underwater mapping using sonar

[ES]El proyecto contiene módulos de simulación, procesado de datos, mapeo y localización, desarrollados en C++ utilizando ROS (Robot Operating System) y PCL (Point Cloud Library). Ha sido desarrollado bajo el proyecto de robótica submarina AVORA.Se han caracterizado el vehículo y el sensor, y se han analizado diferentes tecnologías de sensores y mapeo. Los datos pasan por tres etapas: Conversión a nube de puntos, filtrado por umbral, eliminación de puntos espureos y, opcionalmente, detección de formas. Estos datos son utilizados para construir un mapa de superficie multinivel. La otra herramienta desarrollada es un algoritmo de Punto más Cercano Iterativo (ICP) modificado, que tiene en cuenta el modo de funcionamiento del sonar de imagen utilizado.

BALTHMETRIC SURVEY IN THE KEWEENAW WATER WAY IN MICHIGAN, USA, MAKING 3D MODEL, AND COMPARING SONAR EQUIPMENT OF THE MODERN AUV AND THE TRADITIONAL SINGLE BEAM SONAR

This thesis represents the overview of hydrographic surveying and different types of modern and traditional surveying equipment, and data acquisition using the traditional single beam sonar system and a modern fully autonomous underwater vehicle, IVER3. During the thesis, the data sets were collected using the vehicles of the Great Lake Research Center at Michigan Technological University. This thesis also presents how to process and edit the bathymetric data on SonarWiz5. Moreover, the three dimensional models were created after importing the data sets in the same coordinate system. In these interpolated surfaces, the details and excavations can be easily seen on the surface models. In this study, the profiles are plotted on the surface models to compare the sensors and details on the seabed. It is shown that single beam sonar might miss some details, such as pipeline and quick elevation changes on the seabed when we compare to the side scan sonar of IVER3 because the single side scan sonar can acquire better resolution. However, sometimes using single beam sonar can save your project time and money because the single beam sonar is cheaper than side scan sonars and the processing might be easier than the side scan data.

Recommendations for the use of ultrasound in rheumatoid arthritis: literature review and SONAR score experience

Ultrasound (US) has become a useful tool in the detection of early disease, differential diagnosis, guidance of treatment decisions and treatment monitoring of rheumatoid arthritis (RA). In 2008, the Swiss Sonography in Arthritis and Rheumatism (SONAR) group was established to promote the use of US in inflammatory arthritis in clinical practice. A scoring system was developed and taught to a large number of Swiss rheumatologists who already contributed to the Swiss Clinical Quality Management (SCQM) database, a national patient register. This paper intends to give a Swiss consensus about best clinical practice recommendations for the use of US in RA on the basis of the current literature knowledge and experience with the Swiss SONAR score. Literature research was performed to collect data on current evidence. The results were discussed among specialists of the Swiss university centres and private practice, following a structured procedure. Musculoskelatal US was found to be very helpful in establishing the diagnosis and monitoring the evolution of RA, and to be a reliable tool if used by experienced examiners. It influences treatment decisions such as continuing, intensifying or stepping down therapy. The definite modalities of integrating US into the diagnosis and monitoring of RA treatments will be defined within a few years. There are, however, strong arguments to use US findings as of today in daily clinical care. Some practical recommendations about the use of US in RA, focusing on the diagnosis and the use of the SONAR score, are proposed.

Swath sonar bathymetry during SONNE cruise SO196 with links to multibeam raw data files

Multibeam data were measured during R/V Sonne cruise SO-196 (2008-03-02 to 2008-03-27) along survey profiles, transits and during stationary work. Data were achieved at the Okiwana Trough, particularly in the area of Yonaguni Knoll and Hatoma Knoll. The multibeam sonar system Kongsberg EM120 was operated using 191 beams and up to 150 deg aperture angle. The refraction correction was achieved using CTD profiles measured during this cruise. The quality of data might be reduced during bad weather periods. The dataset contains raw data that are not processed and thus may contain errors and blunders in depth and position.