Fish tracking technology development. Phase 1 project definition desk study

The document reports on Phase 1 of a definition study to appraise the options to develop fish tracking equipment, in particular tags and data logging systems in order to improve the efficiency of the Environment Agency's tracking studies and to obtain a greater understanding of fish biology. Covered in this report are radio telemetry, audio telemetry, High Resolution Position Fixing, data storage and archival tags and other fish tracking systems such as biosonics

Bridges Structural Health Monitoring and Deterioration Detection Synthesis of Knowledge and Technology

INE/AUTC 10.0

Oceanus.

v. 38, no.1 (1995

Wall-Corner Classification Using Sonar: A New Approach Based on Geometric Features

Ultrasonic signals coming from rotary sonar sensors in a robot gives us several features about the environment. This enables us to locate and classify the objects in the scenario of the robot. Each object and reflector produces a series of peaks in the amplitude of the signal. The radial and angular position of the sonar sensor gives information about location and their amplitudes offer information about the nature of the surface. Early works showed that the amplitude can be modeled and used to classify objects with very good results at short distances—80% average success in classifying both walls and corners at distances less than 1.5 m. In this paper, a new set of geometric features derived from the amplitude analysis of the echo is presented. These features constitute a set of characteristics that can be used to improve the results of classification at distances from 1.5 m to 4 m. Also, a comparative study on classification algorithms widely used in pattern recognition techniques has been carried out for sensor distances ranging between 0.5 to 4 m, and with incidence angles ranging between 20° to 70°. Experimental results show an enhancement on the success in classification rates when these geometric features are considered

Applications and prototype for systems of systems swarm robotics

In order to develop a robotic system of systems the robotic platforms must be designed and built. For this to happen, the type of application involved should be clear. Swarm robots need to be self contained and powered. They must also be self governing. Here the authors examine various applications and a prototype robot that may be useful in these scenarios. <br /

Technology Demonstration Report for Underwater Survey Equipment

The underwater equipment technology demonstration report, sponsored by GICHD, provides an evaluation of select commercial technology available for the technical survey of sites contaminated with underwater explosive ordnance. The report, along with the GICHD online equipment catalogue, will assist nations, donors and operators with the selection of the most appropriate equipment for their specific tasks

A Continuous-Time Nonlinear Observer for Estimating Structure from Motion from Omnidirectional Optic Flow

Various insect species utilize certain types of self-motion to perceive structure in their local environment, a process known as active vision. This dissertation presents the development of a continuous-time formulated observer for estimating structure from motion that emulates the biological phenomenon of active vision. In an attempt to emulate the wide-field of view of compound eyes and neurophysiology of insects, the observer utilizes an omni-directional optic flow field. Exponential stability of the observer is assured provided the persistency of excitation condition is met. Persistency of excitation is assured by altering the direction of motion sufficiently quickly. An equal convergence rate on the entire viewable area can be achieved by executing certain prototypical maneuvers. Practical implementation of the observer is accomplished both in simulation and via an actual flying quadrotor testbed vehicle. Furthermore, this dissertation presents the vehicular implementation of a complimentary navigation methodology known as wide-field integration of the optic flow field. The implementation of the developed insect-inspired navigation methodologies on physical testbed vehicles utilized in this research required the development of many subsystems that comprise a control and navigation suite, including avionics development and state sensing, model development via system identification, feedback controller design, and state estimation strategies. These requisite subsystems and their development are discussed

Index to NASA Tech Briefs, 1975

This index contains abstracts and four indexes--subject, personal author, originating Center, and Tech Brief number--for 1975 Tech Briefs

Monitoring the Ocean with Navy Radar Altimeter Lightsats

A system of three radar altimeter LightSats would provide optimum temporal and spatial sampling of the sea surface height signatures of ocean features at mid latitudes and above. Merging this data with satellite infrared images would provide a robust, affordable, all-weather, global ocean monitoring system in support of the Navy Tactical Oceanography mission. The present Navy system for mapping ocean features uses sea surface temperature maps from NOAA satellite radiometers and sea surface height profiles from the Navy GEOSA T radar altimeter satellite. GEOSAT is a 1450-pound, completely redundant satellite with a 207-pound, 165-watt radar altimeter. GEOSAT was developed by JHU/APL and launched in March 1985 on an Atlas-E. A lightsat-compatible radar altimeter instrument has now been developed at APL that achieves full GEOSAT measurement capability In one-half the weight and power (95 pounds and 69 watts), primarily by applying the latest advances in RF and digital components. A form, fit, and function engineering model of the altimeter is being fabricated for performance validation. The conceptual design of GEOSCOUT, a Scout launched version of the GEOSAT satellite, was completed to establish the technical feasibility of the radar altimeter lightsat concept. The spacecraft weight was reduced to 395 pounds and the configuration made Scout-compatible. These weight and volume reductions were made possible by downsizing the instrument, eliminating subsystem redundancy, and by updating subsystem designs. The success of the GEOSCOUT conceptual design has encouraged APL to pursue the next logical step: a combined altimeter/radiometer lightsat. Work on that concept has now begun