Radioisotope Taxi Guidance System Phase I. Feasibility Study

摘要

Methods utilizing radioisotopes as an integral part of an all weather, zero visibility, ground guidance system have been evaluated. The most promising technique has been selected and examined in detail both theoretically and experimentally and a system design is presented. The method employs a stationary avionic gamma ray detector enclosed by a rotating collimator, which senses the position of the aircraft relative to a radioisotopic line source of radiation buried beneath the runway centerline. The avionic unit, approximately one cubic foot in volume, can be mounted in the interior of the aircraft and no structural modifications of the aircraft are required. The information displayed for the pilot is the position of the aircraft relative to the centerline, with an accuracy of better than plus or minus 5 feet at the centerline. The standard radarscope can be used as a display. A key feature of the system is that it uses a chemically inert radioactive gas, krypton-85, which is deployed in the pipe laid in the runway. When not in use the gas can be removed from the runway using conventional gas handling and pumping apparatus. Radiation safety aspects of an operational system have been examined and found to present no hazard beyond normal industrial practice. An additional feature of the radioisotope system is that it can form the basis of an aircraft location and ground control system. The estimated total installation cost of the ground guidance system in a typical airport (Dulles) is about $41,000. The avionic units will cost between $2,300 and $3,300. (Author)