high-frequency direction finding
81crystal — crystallike, adj. /kris tl/, n., adj., v., crystaled, crystaling or (esp. Brit.) crystalled, crystalling. n. 1. a clear, transparent mineral or glass resembling ice. 2. the transparent form of crystallized quartz. 3. Chem., Mineral. a solid body… …
82quantum mechanics — quantum mechanical, adj. Physics. a theory of the mechanics of atoms, molecules, and other physical systems that are subject to the uncertainty principle. Abbr.: QM Cf. nonrelativistic quantum mechanics, relativistic quantum mechanics. [1920 25]… …
83Brevity code — Contents 1 American/NATO codes 1.1 A 1.2 B 1.3 C …
84warning system — ▪ military technology Introduction in military science, any method used to detect the situation or intention of an enemy so that warning can be given. Because military tactics from time immemorial have stressed the value of surprise… …
85Optics — For the book by Sir Isaac Newton, see Opticks. Optical redirects here. For the musical artist, see Optical (artist). Optics includes study of dispersion of light. Optics is the branch of …
86India — /in dee euh/, n. 1. Hindi, Bharat. a republic in S Asia: a union comprising 25 states and 7 union territories; formerly a British colony; gained independence Aug. 15, 1947; became a republic within the Commonwealth of Nations Jan. 26, 1950.… …
87Ultrasound — Not to be confused with Supersonic .Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Although this limit varies from person to person, it is approximately 20 kilohertz (20,000 hertz) in healthy,… …
88Metamaterial — Negative index metamaterial array configuration, which was constructed of copper split ring resonators and wires mounted on interlocking sheets of fiberglass circuit board. The total array consists of 3 by 20×20 unit cells with overall dimensions …
89Crystal — /kris tl/, n. 1. a city in SE Minnesota, near Minneapolis. 25,543. 2. a female given name. * * * I Any solid material whose atoms are arranged in a definite pattern and whose surface regularity reflects its internal symmetry. Each of a crystal s… …
90Letter beacon — Signal of letter beacon D on 5137.5 kHz Letter beacons are radio transmissions of uncertain origin, which consist of only a single repeating Morse Code letter. They are also often referred to as: SLB, or Single Letter Beacons SLHFB, or… …
