Corner reflector

[1][2] To see this, the three corresponding normal vectors of the corner's perpendicular sides can be considered to form a basis (a rectangular coordinate system) (x, y, z) in which to represent the direction of an arbitrary incoming ray, [a, b, c].

Corner reflectors are placed on the vessel's masts at a height of at least 4.6 m (15 feet) above sea level (giving them an approximate minimum horizon distance of 8 kilometers or 4.5 nautical miles).

[4] In optics, corner reflectors typically consist of three mirrors or reflective prism faces which return an incident light beam in the opposite direction.

In surveying, retroreflector prisms are commonly used as targets for long-range electronic distance measurement using a total station.

Automobile and bicycle tail lights are molded with arrays of small corner reflectors, with different sections oriented for viewing from different angles.

Tower blocks with balconies are often accidental acoustic corner reflectors and return a distinctive echo to an observer making a sharp sound noise, such as a hand clap, nearby.