Accession Number : AD0846206

Title :   A Riverbank Echo-Ranging System for Riverine Positioning.

Descriptive Note : Informal rept.,

Corporate Author : NAVAL OCEANOGRAPHIC OFFICE NSTL STATION MS

Personal Author(s) : Breslau, Lloyd ; Tittle, Robert ; Krotser, Don ; Fletcher, James

Report Date : NOV 1968

Pagination or Media Count : 24

Abstract : One way to specify location in a river is to determine lateral (distance along a riverbank) coordinates using the river itself as the prime reference. This technique is particularly useful in an area where map coverage or electronic navigational coverage is inadequate for acceptable riverine positioning. The riverbank echo-ranging system provides only a lateral coordinate and a longitudinal coordinate must be obtained some other way, such as observation of identifiable shoreline features or electronic navigation fixes. Most oceanographic/hydrographic properties of rivers are much more sensitive to lateral positioning error than longitudinal positioning error and consequently a feasible positioning system could solely consist of riverbank echo-ranging and shoreline observation. The Kelvin Hughes Transit Sonar has proved adequate for riverbank is generated on a dry recording strip chart. The Transit Sonar consists of a shipboard recorder and transceiver console requiring 24 volts DC input power, and a hull-mounted transducer. The sonar output is a 1-milli-second pulse at 48 kHz. The significant feature that this instrument has for riverbank ranging lies in the transducer directivity pattern; a 1.5-degree beam in the vertical plane allows discrimination against the river-bottom echo and a 51-degree beam in the horizontal plane provides independence from ship yaw. Recent field tests in the Apalachicola River, Florida, have demonstrated that a clearly identifiably riverbank echo could be obtained up to a distance of 300 yards, which was the maximum distance tested. (Author)

Descriptors :   *ECHO RANGING), (*RIVERS, (*POSITION FINDING, RIVERS), SONAR EQUIPMENT, FEASIBILITY STUDIES, RANGE(DISTANCE), SONAR PULSES.

Subject Categories : Acoustic Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE