Study of Reradiation of LORAN-C In a Harbor Environment.
Abstract
A study is made of the degradation of Loran-C accuracy near overhead conductors such as bridges and power lines. Using a small scale model of the Golden Gate Bridge, amplitude and phase measurement were performed for numerous illumination and position bearings at a variety of distances from the bridge. By sweeping frequency over a 5:1 range, one model simulated a 5:1 range of bridge sizes. The data confirm that up to resonance the large structures can produce large errors (the Golden Gate and Verrazano Narrows bridges are only ten percent below resonant size at 100 kHz) and the smaller bridges produce much smaller errors. The directions of wave incidence and measurement relative to the bridge greatly affect the error, with broadside incidence being worst. The data are compared with full scale measurements. To improve the understanding of how the errors occur, measurements were carried out using modified bridge models with insulators replacing metallic portions. The relationship between reradiation from bridges and power lines is discussed and similarities noted. Some preliminary suggestions for reducing the errors are made, with suggestions for future work. An extensive literature review and bibliography are included.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 08, 1982
- Accession Number
- ADA120624
Entities
People
- Robert L. Frank
- Valdis V. Liepa
Organizations
- University of Michigan