This paper applies acoustic principles and a novel scanning method motivated by acoustic flow to recognize retro-reflectors directly from sonar echoes while performing drive-by scanning. Right-angle corners and cylinders form specular retro-reflectors that produce strong echoes whose features can be easily identified. A multi-point sonar produces a point process whose density encodes the echo a...

[1] Recent advances in underwater vehicle navigation and sonar technology now permit detailed mapping of complex seafloor bathymetry found at mid-ocean ridge crests. Imagenex 881 (675 kHz) scanning sonar data collected during low-altitude ( 5 m) surveys conducted with DSV Alvin were used to produce submeter resolution bathymetric maps of five hydrothermal vent areas at the East Pacific Rise (EP...

This paper addresses the problem of mapping the features of a gas distribution by creating concentration gridmaps with a mobile robot equipped with a gas-sensitive system (“mobile nose”). By contrast to metric gridmaps extracted from sonar or laser range scans, a gas sensor measurement provides information about a comparatively small area. To overcome this problem, a mapping technique is introd...

Echolocating bats construct an auditory world sequentially by analyzing successive pulse-echo pairs. Many other mammals rely upon a visual world, acquired by sequential foveal fixations connected by visual gaze saccades. We investigated the scanning behavior of bats and compared it to visual scanning. We assumed that each pulse-echo pair evaluation corresponds to a foveal fixation and that sona...

Traditional approaches to AUV collision avoidance involve the adaptation of COTS electronic scanning sonars that have been designed for applications where low power is not a consideration. This has an adverse impact on the endurance and performance of the AUV. The navigation and obstacle avoidance processing is typically performed by the vehicle control processor, acting on large volumes of dat...

This paper describes an approach to autonomous navigation for an undersea vehicle that uses information from a scanning sonar to generate navigation estimates based on a simultaneous localization and mapping algorithm. Development of low-speed platform models for vehicle control and the theoretical and practical details of mapping and position estimation using sonar are provided. An implementat...

A 252 channel FM sonar is developed to generate images of objects buried in sediments using reflection tomography. An omnidirectional source, transmitting FM pulses over the band of 2 to 12 kHz, illuminates buried targets. The backscattered signals are measured with 252 hydrophones and processed with a digital matched filter. Coherent nearfield focusing generates a 3D map of acoustic intensity ...