The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Ray optics theory is applied to a particular case of oil polluted layer, caused by some underwater source. Two-layered ocean model is considered; layer one is of saline water of the ocean and layer two, oil polluted saline water. Both of these layers are assumed to be linearly inhomogeneous. Ray paths are traced in the above said type of medium and the associated errors present are calculated. Computer...
Resolution of echo sounders and sub-bottom profilers is limited by the beamwidth of the system. Beamwidths of2\degor so are desired, but at the low operating frequencies required by attenuation of the signals the apertures become very large. A method based on the inherent nonlinearity of the acoustic medium at high intensities (the finite amplitude effect) has been developed which permits an order...
Conventional electrical hull penetrators for deep-submersible applications employing pressure-resistant construction become prohibitively heavy when designed for reliable operation at 20,000 ft depth. Outboard cable assemblies employing conventional helical-lay conductors with a heavy rubber jacket and attached to the back shell of pressure-proof electrical connectors by rubber-molding or similar...
Careful control of the environment in a hyperbaric facility is necessary to protect the health and well-being of the occupants. In this paper total environmental control in the hyperbaric chamber is broken down into eight categories of control: total pressure, O2partial pressure, CO2partial pressure, temperature and humidity, trace contaminants, fire detection, bacteria and noise. For each category...
The Naval Torpedo Station collaborated with the University of Washington, Department of Oceanography, to develop a calibration technique for inductive conductivity probes. The basically simple technique uses an empirical relationship between salinity, temperature and conductivity developed at the University. Development of the salinity-conductivity-temperature relationship is presented. Confinement...
Can off-the-shelf electronic components be used in the deep ocean without protection from the very high hydrostatic pressure? This paper describes a test philosophy and a unique facility designed to answer this question and to determine the mechanisms of failure that are encountered under severe pressure. The facility consists of three pressure vessels, each having 150 electrical penetrators and a...
Acoustic signals from Dungeness crabs of known size and sex have been collected and analyzed. The digital analysis included computation of the autocorrelation function and the power spectral density of each signal. The relationship between spectral resolution, statistical error and signal length was considered. Several different spectral windows were applied. The width of the window was found to have...
This project is four years old. The scope of this grand concept was to project man's technical capability to the limits of the ocean volume, and beyond, in support of National security and non-defense goals. Four years in the rational, financial world of DOD has changed the scope of the technology demonstrations but not the quality of the advanced technology goals originally set. The current project...
Development of a microminiature self-contained underwater binaural communications set for the military diver has been completed at the Naval Ship Research and Development Laboratory, Panama City, Florida (NAVSHIPRANDLAB, Panama City). The primary objectives were high intelligibility, reliability, and ease of operation. The equipment features voice operated transmission (to free the diver's hands),...
Our goal is to extend the reach of man to the depths of the hostile ocean environment. Experience indicates that the best approach is the use of electro-hydraulic manipulators. For a decade NUC has been doing useful work in the sea with remotely controlled hydraulic devices. These devices have ranged from the early three-function "claw" of the Cable-controlled Undersea Research Vehicle,...
Extensive gravity anomaly coverage is required in formulating an accurate gravity perturbation vector. Stokes' and Meinesz's integral formulas are presently used in calculating the gravity vector. However, a two-dimensional Fourier series approach to data representation is presented which efficiently functionalizes the data so as to minimize the computational complexity involved in determining the...
Simulation of large-scale pollution problems is most often subject to identification of important physical constants. Moreover, the inherent randomness of the surroundings in which identification is to take place compounds the analytical difficulties. In some cases the analysis must consider the distributed parameter system. This paper presents results which advance ocean pollution identification...
This Center has set up a unique sonar range between the tops of two seamounts in the Pacific Ocean. The great distance from the end points to shore has precluded the routing of power and control cables to manned stations and has, consequently, given rise to some unusual instrumentation. The transmitting station was pre-programmed on implantment in June 1969 to broadcast a wide variety of frequencies...
An electronic subsystem was developed for on-line, real-time digital and graphical conversion of coordinates derived from a range-range mode electronic precision positioning and navigation system. The application of this development is well suited to high density tight-grid marine surveys, especially where accuracy and relocation of a few feet are required as in undersea mining and mineral deposit...
A simulation model has been formulated for the parametric analysis of the capabilities of advanced underwater viewing systems and to facilitate the comparison of the different systems. The water medium is characterized in the model by the absorption coefficient,a, the scattering coefficient,s, the volume scattering function,\sigma, and the polarization coefficient,\psi_{p}, of the backscattered light...
The viewing range and resolution capabilities of underwater television systems are often limited due to absorption and scattering properties of sea water. An additional problem with present systems is the lack of display realism needed for close vehicle guidance and effective control of undersea teleoperator systems. This paper discusses various imaging techniques which can be used to improve underwater...
In spite of technological advances in instrument design, data centers continue to encounter data management problems when processing, storing and retrieving marine data. This paper describes the Environmental Data Service's (EDS), National Oceanic and Atmospheric Administration (NOAA), U. S. Department of Commerce, concept of data management, the importance of utilizing what is already known about...
Three basic approaches to acoustic imaging are described: focused imaging, which uses acoustic lenses or reflectors to form an image; holographic imaging, which reconstructs images from detected wavefronts; and high-resolution beamforming imaging, which maps the object plane into the image plane by scanning. For each system type, possible hardware implementations are described with specific examples...