External: allow the interpretation of the surrounding environment. They provide information about: • object proximity – the presence/absence of an object and the distance between objects;• physical orientation – the coordinates of an object in space;• heat – the wavelength of infrared or ultra violet rays, temperature, magnitude, direction;• chemicals – the presence, identity, and concentration of chemicals or reactants;• light – the presence, colour, and intensity of light;• sound – the presence, frequency, and intensity of sound.
LIDAR (Light Detection And Ranging) is an example of a sensor. LIDAR is a technology that uses a laser to measure distance. Lasers illuminate objects in an environment and reflect the light back. The robot analyzes these reflections to create a map of its surrounding environment.