Martel (missile) Martel (missile) The Martel is an Anglo-French anti-radiation missile (ARM). The name Martel is a contraction of "Missile, Anti-Radiation, Television", referring to the guidance options. There are two variants, the passive radar guided (AS 37) and the video guided (AJ 168). The aircraft that used these missiles were the Blackburn Buccaneer (up to three TV or four ARM variant), the SEPECAT Jaguar (two), the Mirage III/F1 (one or two), and the Hawker Siddeley Nimrod (at least one). The Martel was suited to anti-ship attack with its long range and heavy warhead. There was not, at the time, a small radar
Refraction medicine, particularly optometry, ophthalmology and orthoptics, "refraction" (also known as "refractometry") is a clinical test in which a phoropter may be used by the appropriate eye care professional to determine the eye's refractive error and the best corrective lenses to be prescribed. A series of test lenses in graded optical powers or focal lengths are presented to determine which provides the sharpest, clearest vision. In underwater acoustics, refraction is the bending or curving of a sound ray that results when the ray passes through a sound speed gradient from a region of one sound speed to a region of a