Retroreflectance of Wires and Cables at 10.6 Micrometers

摘要

Quantitative measurements of reflectance are made for a variety of field wires using an infrared laser operating at 10.6 micrometers. Results are presented as plots of retroflectance versus viewing angle for stranded metallic, insulated, and weathered wires and cables in wet and dry states. Performance implications are discussed for a possible wire avoidance system. Retroflectance is found to be greatly decreased for the wet wires. For the case of 6mm diameter copper wire the reduction of retroflectance at normal incidence of approximately 15 dB results in a decrease of detection range from 3.6 to 1.8km for a typical wire detection system. Weathered wires are shown to have a much more diffuse retroflectance distribution. For the 6mm copper wire, retroflectance of the weathered sample is lower than that of the unweathered by 10 dB at normal incidence, but is higher by 10 dB at 50 degrees. This results in a decrease of detection range from 3.7 to 2.4km at normal incidence and an increase from 1.3 to 2.0km at 50 degrees.