Evaluation of a Multiple FM/CW Radio Altimeter Installation

摘要

Interference effects in multiple radio altimeter installations were investigated. Three FM/CW radio altimeters in one aircraft were operated simultaneously over various types of terrain. Mutual interference between altimeters was not significant under normal operating conditions. Differences of indicated altitude occurred between altimeters over irregular terrain. The differences were pronounced when the antenna patterns of the altimeters were skewed with respect to one another. The differences were not significant when the antenna patterns were approximately coincident. It was recommended that multiple antenna installations be designed to provide nearly coincident beam axes. (Author)