Accession Number : ADA192069

Title :   Descriptions of HF and VHF Loran-C Buoys and Evaluations as Potential Datum Marker Buoys.

Descriptive Note : Interim rept.,

Corporate Author : COAST GUARD RESEARCH AND DEVELOPMENT CENTER GROTON CT

Personal Author(s) : Allen, Arthur A ; Eynon, Sandra L ; Robe, R Q

PDF Url : ADA192069

Report Date : Sep 1987

Pagination or Media Count : 45

Abstract : The U.S. Coast Guard Research and Development Center has tested two types of Loran-C drifting buoys as prototypes for replacements for the presently used Radio Direction Finder (RDF) type Datum Marker Buoys (DMB). The buoys used HF or VHF transmission of the buoy's Loran-C Time Differences to a shore/ship based receiver at 10 to 100 minute intervals. Field testing of the buoys at sea occurred off Cape Cod, MA; Cape May, NJ; and Georges Bank, MA. Of the two types of buoys the one using VHF technology proved to be more suitable for future development than that using HF technology. The main reasons for the better results with the VHF versus HF buoys was simplicity and reliability. Results indicated that the VHF buoys can survive severe weather, transmit data reliably, and have sufficient range for useful tracking and data collection. Tests indicated reliable data reception at 20 nautical miles (nm) from a vessel and 50-60 nm from an airborne receiver. The advantage of the Loran-C buoys over the RDF DMB is the increased data collection rate and that the data collection does not interrupt the ongoing search. The Loran-C buoys are being incorporated into a system to be used to establish a working search datum and for defining the sea surface currents of the search area in real-time.

Descriptors :   *BUOYS, *LORAN, *RECEIVERS, AIRBORNE, COAST GUARD RESEARCH, DATA ACQUISITION, DATA RATE, DRIFT, FIELD TESTS, FISHES, MARKERS, OCEAN CURRENTS, OCEAN SURFACE, RELIABILITY, SEARCHING, SHIPS, SHORES, STORMS, TIME, TRACKING, VERY HIGH FREQUENCY

Subject Categories : Underwater and Marine Navigation and Guidance

Distribution Statement : APPROVED FOR PUBLIC RELEASE