Abstract: Improved radar guidance system for the navigation apparatus of an aircraft s it flies over substantially flat terrain with random and different features. The system is generally made up of an airborne radar altimeter, a video signal processor and a master processor. The altimeter transmits a series of pulses at predetermined time intervals for impacting a plurality of spaced points along the aircraft ground track. The echo signal of each pulse-impacted point processor divides the amplified signal into corresponding signals. A comparator of the signal processor transforms one of the divided signals into a constant output. A track and hold arrangement of the signal processor correlates the delayed leading edge of the comparator output with the other of the divided signals so as to determine a point of intersection therebetween.

Abstract: A spliceless optical-fiber resonant-ring laser gyroscopic system is disclosed. The spliceless optical-fiber resonant-ring gyroscopic system includes a cylindrically-shaped monolithic housing fashioned from a material having an ultra-low coefficient of thermal expansion. A selected length of optical-fiber is mounted about the perimeter of the cylindrically-shaped housing and closed on itself to form an optical-fiber ring having at least one turn. The spliceless optical-fiber ring and an evanescant-wave directional coupler are provided by bringing the fiber proximate to the ends of the optical-fiber ring in parallel contiguity. A narrow-band gas-discharge helium-neon optical-frequency tunable laser is formed within the monolithic housing and operatively connected to the ends of the spliceless optical-fiber ring via an integrated-optics chip.