Parmi l'ensemble des sondeurs qui peuvent équiper un véhicule marin, le DVL (Doppler Velocity Log) est celui qui mesure la vitesse de déplacement par rapport au fond de la mer. Comme la localisation par satellites est indisponible sous l'eau, le DVL devient indispensable pour la navigation et la précision de localisation géographique sous-marine.Po...
Existing sonar systems typically rely on a minimum signal strength of a single echo, which limits their performance in low signal-to-noise conditions. This thesis explores the concept of coherent integration for active sonar, with the aim of improving imaging and detection capabilities under low signal-to-noise conditions. The goal is to provide si...
In underwater acoustics, environmental fluctuations can lead to a loss of coherence in sonar arrays. Among the various approaches that can be considered to mitigate their effects, sub-array processing is a popular and intuitive one. However, it naturally results in sub-optimal performance. In this paper, we propose to enhance the approach in two wa...
This paper presents the new RTAC acoustic simulator aimed at embedded use on low power GPUs. The purpose of this simulator is to be used for relocalisation tasks based on front scan sonars for Autonomous Underwater Vehicles in already mapped environments. Relocalisation is to be achieved by registration of the real and estimated sonar images. The R...
The Interferometric DVL (InDVL) is a new instrument designed to be free from acoustic bias. The InDVL combines pulse-to-pulse phase comparison, used by all wideband Doppler sonars, with element-to-element phase comparison generally used for direction finding. The most general InDVL receiver array design consists of a 3D ultrashort baseline, with fo...
Orientador: Marcelo Renato Lamour / Monografia (graduação) - Universidade Federal do Paraná, Campus Pontal do Paraná, Centro de Estudos do Mar, Curso de Graduação em Oceanografia / Inclui referências / Resumo : As feições de fundo, distribuídas ao longo dos leitos de desembocaduras de estuários, podem servir como grandes aliados nas interpretações ...
Background Maritime transportation is vital for international trade, and any disruption to this flow can have severe financial and environmental consequences. Ship mines, both old and new, present significant risks as man-made obstacles. The perilous task of minesweeping, historically carried out by humans at great risk, necessitates the developmen...
Full coverage of an area of interest is a common task for a robot in the underwater environment. Estimating the area explored by the robot is indeed essential for determining if path-planning algorithms lead to complete coverage. In this work, we propose a method for estimating the area explored by a Side-Scan Sonar. The proposed method is able to ...
Un sous-marin dispose d'une antenne linéaire remorquée et éventuellement d'antennes montées sur ses flancs pour détecter et localiser les sources d'intérêt. Pour les sources en mouvement, il dispose d'une fonction trajectographie en aval de son système sonar. L'antenne linéaire remorquée délivre des mesures de cosinus de pseudo-gisements fournies p...
Published in at - Automatisierungstechnik
The paper describes an autonomous water vehicle (ASV) capable of autonomously mapping shallow water environments above and below the water surface. Over the past two years, Fraunhofer IOSB has developed a system that is fully electrified and equipped with extensive sensor technology (multibeam sonar, lidar, cameras, IMU, GNSS). For autonomous navig...
