A Low Approach System for Helicopters

The proposed low approach system for steep gradient is a C-band, CW/AM system with side lobe suppression and frequency diversity. It consists of an airborne receiver system, ground transmitter system, and a ground monitoring system. The complete airborne package is solid state, as is the ground installation with the exception of the power amplifier. The proposed system offers high reliability, immunity to multipath, small antenna sizes, and simplicity while still using completely conventional techniques. It also affords easy incorporation of a Distance Measuring Equipment capability.