A sonar-based mapping and navigation system developed for an autonomous mobile robot operating in unknown and unstructured environments is described. The system uses sonar range data to build a multileveled description of the robot’s surroundings. Sonar readings are interpreted using probability profiles to determine empty and occupied areas. Range measurements from multiple points of view are ...

| This paper is concerned with hierarchical Markov Random Field (MRF) models and their application to sonar image segmentation. We present an original hierarchical seg-mentation procedure devoted to images given by a high resolution sonar. The sonar image is segmented into two kinds of regions: shadow (corresponding to a lack of acoustic reverberation behind each object lying on the sea-bed) an...

This paper describes the application of using a submersible remotely operated vehicle (ROV) to map and explore underground water cisterns during a series of expeditions to Malta and Gozo. The purpose of this project was to create maps of ancient cisterns located under private homes, churches, and fortresses where passageways leading to the cisterns are too narrow and dangerous for humans to ent...

We propose to combine a biomimetic navigation model which solves a simultaneous localization and mapping task with a biomimetic sonar mounted on a mobile robot to address two related questions. First, can robotic sonar sensing lead to intelligent interactions with complex environments? Second, can we model sonar based spatial orientation and the construction of spatial maps by bats? To address ...

Echolocating bats exhibit accurate three-dimensional (3D) auditory localization to avoid obstacles and intercept prey. The bat achieves high spatial resolution through a biological sonar system. Key features of the bat's sonar system are (1) high frequency, directional echolocation signals; (2) high frequency hearing; (3) mobile ears; and (4) measurement of distance from the time delay between ...

Anthropogenic underwater sound in the environment might potentially affect the behavior of marine mammals enough to have an impact on their reproduction and survival. Diving behavior of four killer whales (Orcinus orca), seven long-finned pilot whales (Globicephala melas), and four sperm whales (Physeter macrocephalus) was studied during controlled exposures to naval sonar [low frequency active...

This paper describes a mobile robot equipped with a sonar sensor array in a guided feature based map building task in an indoor environment. The landmarks common to indoor environments are planes, corners and edges, and these are located and classified with the sonar sensor array. The map building process makes use of accurate odometry information that is derived from a pair of knife edged unlo...

Target recognition in sonar imagery has long been an active research area in the maritime domain, especially in the mine-counter measure context. Recently it has received even more attention as new sensors with increased resolution have been developed; new threats to critical maritime assets and a new paradigm for target recognition based on autonomous platforms have emerged. With the recent in...

This paper is concerned with hierarchical Markov random field (MRP) models and their application to sonar image segmentation. We present an original hierarchical segmentation procedure devoted to images given by a high-resolution sonar. The sonar image is segmented into two kinds of regions: shadow (corresponding to a lack of acoustic reverberation behind each object lying on the sea-bed) and s...

Passive sonar sensors are the main source of information for a submerged submarine. Modern sonar systems like ISUS 90 offer a number of acoustic antennas and combined signal processing for broadband and narrowband detection and analysis of target noise. While broadband detection is often used to obtain an overview of the targets surrounding the own ship, narrowband processing enables the detect...