THE DEVELOPMENT ADJUSTMENT, AND APPLICATION OF THE Z-MARKER

摘要

The Z-marker was developed to meet the need for a positive position indicator for aircraft operating under instrument flying conditions which would otherwise have to depend entirely upon the "cone of silence" as an indication of passage directly over a ranger station. The marker consists of a low power transmitter and directive antenna array, operating on a frequency of 75 megacycles, which projects a vertical beam through which aircraft will pass when flying over the range station.