Abstract: A radar method and apparatus which utilizes a first frequency signal modued by a first modulating signal and a second frequency signal modulated by a second modulating signal, the first and second frequencies being different and the first and second modulating waveforms having different periods of repetition. The radar receiver separates the return radar signal into the component due to the first frequency signal and the component due to the second frequency signal. Both components are then heterodyned with their respective frequency signals. Each modulating waveform is subjected to a plurality of delays and each component is subsequently correlated with each of its respective delayed modulating waveforms. A target is recognized when the correlated first frequency component exceeds a predetermined threshold and simultaneously the correlated second frequency component exceeds a predetermined threshold.

Abstract: In an optical data bus system, a fail-safe optical repeater-amplifier assly is provided by light energy amplifying means connected in the data bus for developing gain of signal strength for light signals transmitted along the data bus in a known direction. The light energy amplifying means is connected in parallel with a passive, non-amplifying light path, the light path having an optical length for impressing a delay on light signals passing therethrough which is substantially equal to the optical delay imposed by transmission through the light energy amplifying means.

Abstract: A pulsed laser produces emitted laser energy by dissociative excitation of etal dihalide and cyclic recombination. A metal dihalide selected from subgroup II-B of the periodic table of elements is contained within an elongate sealed enclosure. Two elongate electrodes having external terminals are supported in parallel relationship within the enclosure, forming a gap parallel to the principal axis of the enclosure. A source of pulsed electric power is connected to the terminals of the two electrodes, producing repetitive transverse electric discharges across the gap. An inert buffer gas is included within the enclosure for aiding electric discharge uniformity, and to provide vibrational relaxation of the lasing medium in its electronic states.