Anti-radiation missile of radiation and explode when they got near it. SAM operators learned to turn their radar off when an ARM was fired at them, then turn it back on later, greatly reducing the missile's effectiveness. This led to the development of more advanced ARMs such as the AGM-78 Standard ARM and AGM-88 HARM missiles, which have inertial guidance systems (INS) built-in. This allows them to remember the radar's direction if it is turned off and continue to fly towards it. ARMs are less likely to hit the radar if the radar is turned off shortly after the missile is launched,
Negative refraction propagation direction of the light, thus the sign of "n" must be chosen to match the physical situation. The principal symptom of negative refraction is just that – light rays are refracted on the "same" side of the normal on entering the material, as indicated in the diagram, and by a suitably general form of Snell's law. Negative refraction Negative refraction is the name for an electromagnetic phenomenon where light rays are refracted at an interface in the reverse sense to that normally expected. Such an effect can be obtained using a metamaterial which has been designed to achieve a