Python (missile) that of US FIM-92 Stinger (infrared homing and ultraviolet), with IRCCM (IR ECCM) ability to reduce background IR radiation to reduce the effectiveness of enemy flares. The Python-5 is currently the most capable air-to-air missile in Israel's inventory and one of the most advanced AAMs in the world. As a beyond-visual-range missile, it is capable of "lock-on after launch" (LOAL), and has full-sphere/all-direction (including rearward) attack ability. The missile features an advanced electro-optical infrared homing seeker which scans the target area for hostile aircraft, then locks-on for terminal chase. With a total of eighteen control surfaces and careful design, the
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