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
Optic axis of a crystal Optic axis of a crystal An optic axis of a crystal is a direction in which a ray of transmitted light suffers no birefringence (double refraction). An optical axis is a direction rather than a single line: all rays that are parallel to that direction exhibit the same lack of birefringence. Crystals may have a single optic axis, in which case they are "uniaxial", or two different optic axes, in which case they are "biaxial". Non-crystalline materials generally have no birefringence and thus, no optic axis. A uniaxial crystal (e.g. calcite, quartz) is isotropic within the plane orthogonal to the