This tutorial involves implementing sonar processing algorithms and applying them to real underwater hydrophone data collected in the ocean. The goal of the tutorial is to learn how to apply the time-difference of arrival (TDOA) method to acoustic data recorded on two hydrophones to obtain a bearing estimate. TDOA processing is a classic passive sonar problem, and is also forms basis for many o...

A binaural sonar sensor for blind persons which models the bat sonar is described. System performance with field plots are presented along with signal analysis on objects forming targets. The distal spatial resolution is little more than one wavelength at the lowest frequency of 50 kHz. The operating bandwidth is 50 kHz producing the power to discriminate between objects. Distance and direction...

This paper is concerned with the problem of object recognition using a sonar sensor array. The sonar returns are preprocessed and fed to a support vector machine (SVM) classifier to carry out the recognition. We demonstrate that it is possible to gradually improve recognition performance by using a genetic algorithm to select a sequence of subsets from the available training data. Performance i...

This paper describes a new method by which a mobile robot can construct a map of its environment from sonar sensory data. A model of sensor behaviour is used to construct a probability function on the space of all maps, which is then searched for the map of highest probability. Because of the very large dimension of this space, specialised search techniques are required. The algorithm was teste...

This paper describes a new highly accurate fast selfcontained sonar sensor. Transmission and echo analysis are performed at repetition rates exceeding 27 Hz for ranges to 5.4 metres. The sensor contains low noise variable gain preamplifiers, two 1 MHz 12 bit ADC receivers and a DSP echo processor. Optimal arrival time estimation is performed by the DSP using matched filtering of echoes with sho...

This paper describes a radio frequency identification (RFID) and sonar-guided tour guide robot, CATE (Central’s Automated Tour Experience). The portable terminal unit is an embedded system equipped with an RFID reader for localization, and sonar and IR sensors for obstacle detection and avoidance. CATE can guide the visitor through a predefined tour of the building, or create a new route onthe-...

This paper describes an advanced sonar ring that employs a low receiver sample rate to achieve processing of 48 receiver channels at near real time repetition rates of 15 Hz. The sonar ring sensing covers 360 degrees around the robot with simultaneously firing of 24 transmitters. The receiver sampling frequency is 250 kHz, compared to previous work at 1 MHz, firstly to maximize the speed of pro...

A novel electronic sensing system (SAS2) was designed to non-invasively and simultaneously measure snow density, liquid water content, and temperature of snow using acoustics and obtain images of the snowpack. The system is an updated andmore sophisticated version of previous acoustic sensing systems, and this paper presents an update on the development of acoustic sensing methods to measure mu...

Map building is one of the most popular classical problems in mobile robotics field and sensor model is the way to interpret raw sensory information in spatial world especially for building map. For mobile robots, working in indoor environment, Ultrasonic Sonar(US) is famous because of its availability, wide angle and long range sensing ability etc, in spite of some problems. Among them, Specul...

In present missions of submarines, the detection of hostile targets is one of the main objectives. To achieve these objectives modern submarines are well equipped with sonar sensors and signal processing units for all acoustical frequency ranges. The detection and analysis of silent or distant targets is the main task of towed array systems. Towed arrays have their advantages in the low frequen...