Download or read book A Preliminary Study of Shallow water Sonar Issues written by W. Kenneth Stewart and published by . This book was released on 1993 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cruise Report written by Ellyn T. Montgomery and published by . This book was released on 1993 with total page 684 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1994 with total page 1596 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Underwater Robots written by Junku Yuh and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt: All life came from sea but all robots were born on land. The vast majority of both industrial and mobile robots operate on land, since the technology to allow them to operate in and under the ocean has only become available in recent years. A number of complex issues due to the unstructured, hazardous undersea environment, makes it difficult to travel in the ocean while today's technologies allow humans to land on the moon and robots to travel to Mars . . Clearly, the obstacles to allowing robots to operate in a saline, aqueous, and pressurized environment are formidable. Mobile robots operating on land work under nearly constant atmospheric pressure; their legs (or wheels or tracks) can operate on a firm footing; their bearings are not subjected to moisture and corrosion; they can use simple visual sensing and be observed by their creators working in simple environments. In contrast, consider the environment where undersea robots must operate. The pressure they are subjected to can be enormous, thus requiring extremely rugged designs. The deep oceans range between 19,000 to 36,000 ft. At a mere 33-foot depth, the pressure will be twice the normal one atmosphere pressure of 29. 4 psi. The chemical environment of the sea is highly corrosive, thus requiring the use of special materials. Lubrication of moving parts in water is also difficult, and may require special sealed, waterproof joints.

Download or read book An Entropic Framework for AUV Sensor Modelling written by Hanumant Singh and published by . This book was released on 1995 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis examines the general task of active sensing by defining a measure of efficiency for sensing in a particular environment. We focus on fine-scale acoustic mapping from an autonomous underwater vehicle (AUV). The constraints on imaging underwater - vehicle power, vehicle hydrodynamics, computational and telemetry requirements, and typical navigational and attitudinal uncertainties along with the underlying physics of the acoustic sensing modality- are considered in defining an entropic measure of sensor efficiency. 675-kHz pencil-beam sonar data acquired using the JASON remotely operated vehicle in a challenging shallow water environment and 200-kHz echo-sounder data acquired using the ABE A UV are used to demonstrate the utility of the en tropic framework. We show the utility of an entropic framework for the following: (i) Optimizing the speed of the AUV for maximizing the information gathered with a particular sensor. (ii) the rate of convergence and the stability of our mapping efforts in the face of typical uncertainties in navigation and attitude; (iii) as a methodology for actual sensor deployment and use on a real vehicle; and (iv) in tasks such as post-mission analysis for applications such as change detection and path planning for subsequent missions.

Download or read book Government Reports Annual Index written by and published by . This book was released on 1994 with total page 1106 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High frequency Reverberation in Shallow Water written by and published by . This book was released on 1997 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper examines whether it is possible to model the prevalent features of shallow-water reverberation by employing a sonar system model such as the Generic Sonar Model (GSM). To study this issue, data were collected over the 20-40 kilohertz frequency band in 100 metres of water on La Have Bank off Nova Scotia using a horizontally pointing sonar suspended to a depth of 42 metres. The paper describes the experimental procedure & equipment and the bottom topography of the experimental site. The reverberation data are then presented & compared with estimates obtained using GSM. The most interesting feature of the data is examined in light of the model results and the eigenrays interacting with the bottom.

Download or read book Report WPG written by United States. Office of Scientific Research and Development. National Defense Research Committee. Committee on Propagation and published by . This book was released on 1944 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings of the Technology and the Mine Problem Symposium written by Albert M. Bottoms and published by . This book was released on 1996 with total page 978 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Model Sonar Technique for Shallow Water written by Arthur St. Clair Wright and published by . This book was released on 1969 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experiment was performed in a small laboratory tank to study the feasibility of modeling an active sonar in a shallow water environment. The modeling frequency of 1000 kHz in a two meter tank indicated fair compatibility with theory for the short scaled ranges studied. An initial spherical spreading loss followed by a cylindrical spreading loss, bottom loss effects, and Lloyd mirror interference were observed. The methods were observed. The methods were suitable for future modeling experiments. (Author).

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 994 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Technical Abstract Bulletin written by and published by . This book was released on with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Marine Research written by and published by . This book was released on 1969 with total page 764 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book U S Fish and Wildlife Service National Oceanic and Atmospheric Administration and National Marine Fisheries Service Budget Requests for Fiscal Year 2002 written by United States. Congress. House. Committee on Resources. Subcommittee on Fisheries Conservation, Wildlife, and Oceans and published by . This book was released on 2002 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book SBIR Pre solicitation Announcement written by and published by . This book was released on 1986 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The CERCular written by and published by . This book was released on 1993-12 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Department of Defense Appropriations for 1996 written by and published by . This book was released on 1997 with total page 706 pages. Available in PDF, EPUB and Kindle. Book excerpt: