OTH Radar Surveillance at WARF During the LRAPP Church Opal Exercise
Abstract
In September 1975, the Wide Aperture Research Facility (WARF) Over- the-Horizon Radar (OTHR) performed shipping surveillance as part of the Long- Range Acoustic Propagation Project (LRAPP) exercise Church Opal. The purpose of the OTHR experiment was to help determine the density and distribution of ships in three Pacific Ocean areas, each 5 deg by 5 deg square. The noise emitted by ships sometimes reduces the sensitivity of underwater acoustic systems. Over a period of five days, 26 separate ships were detected and tracked at WARF. An ocean area of approximately 250,000 sq km was searched eight times each day. The largest number of ships detected was nine, and the smallest was two, on any given day. Ship radial speeds ranged between 11 and 23 knots, and estimated ship lengths varied between 300 and 650 ft or more. OTHR and P3 ship density results were compared on the last day of WARF operation, and the agreement was good. By comparison, however, the correlation of the positions of individual ships reported by P3 and OTH radars was relatively poor. Both high probability OTH detections and P3 detections were apparently not seen by the opposite sensor. Church Opal was the second of three recent formal tests of the OTHR ship surveillance capability at WARF. It was the first time that any OTHR had routinely searched large ocean areas for surface shipping. The wide-area ship surveillance performed by OTHR in this experiment demonstrated utility for this and similar ocean surveillance applications. Recommendations for future work are discussed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1976
- Accession Number
- ADC010483
Entities
People
- James R. Barnum
Organizations
- SRI International