A Tactical Aircraft Landing Aid

A need exists for a tactical landing aid which will perform many of the functions of conventional ILS systems, but is portable, simple to install and is inexpensive. To meet this need, a system designated as TALAR?? for tactical landing aid-radio has been developed. In this system a conically scanning cassegrain antenna operating at 15.5 GHz in conjunction with a magnatron transmitter radiates energy from the ground which is received by a lightweight 4 pound receiver in the aircraft. The transmitter energy is modulated by means of a 100 kHz sub-carrier and undergoes additional modulation because of spatial position within the scanned beam. At beam center this spatial modulation is zero. A reference is provided by means of FM placed on the 100 kHz sub-carrier so that by phase-detection the aircraft position in both glide-slope and localizer can be displayed on a conventional cross-pointer instrument. The transmitter weighs approximately 35 pounds and consumes about 220 watts input power. It can be set up in 10-15 minutes by semi-skilled personnel. Range exceeds 10 nautical miles (18.3 Km) while the overall localizer beamwidth is approximately ?? 15 degrees and glide-slope coverage is ?? 3 degrees.