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Currently issued in the USMC, the AN/PEQ-16B helps to consolidate the number of attachments on the hand guards of infantry weapons, including the visible, and infrared lasers, an infrared illuminator, and a white-light illuminator for urban or dark environments where night vision devices may be impractical or not available.
The beams can only be seen through night vision goggles. [9] Each beam can be zeroed independently, and the illuminator's radius is adjustable. The two lasers are tied into one 6-mode switch, which has the following modes:
When seen from below by a predator, the animal's light helps to match its brightness and colour to the sea surface above. Counter-illumination is a method of active camouflage seen in marine animals such as firefly squid and midshipman fish, and in military prototypes, producing light to match their backgrounds in both brightness and wavelength.
Security lighting to prevent intrusions may be counter-productive. Turning off lights halved the number of thefts and burglary in Övertorneå Sweden. [2] [3] A test in West Sussex UK showed that adding all-night lighting in some areas made people there feel safer, although crime rates increased 55% in those areas compared to control areas and to the county as a whole.
Passive radar (also referred to as parasitic radar, passive coherent location, passive surveillance, and passive covert radar) is a class of radar systems that detect and track objects by processing reflections from non-cooperative sources of illumination in the environment, such as commercial broadcast and communications signals.
Thayer's 1902 patent application. He failed to convince the US Navy. The English zoologist Edward Bagnall Poulton, author of The Colours of Animals (1890) discovered the countershading of various insects, including the pupa or chrysalis of the purple emperor butterfly, Apatura iris, [2] the caterpillar larvae of the brimstone moth, Opisthograptis luteolata [a] and of the peppered moth, Biston ...
Photophores on fish are used for attracting food or for camouflage from predators by counter-illumination. [ citation needed ] Photophores are found on some cephalopods including the firefly squid , which can create impressive light displays, as well as numerous other deep sea organisms, such as the pocket shark Mollisquama mississippiensis and ...
A transparency of 50 per cent is enough to make an animal invisible to a predator such as cod at a depth of 650 metres (2,130 ft); better transparency is required for invisibility in shallower water, where the light is brighter and predators can see better. For example, a cod can see prey that are 98 per cent transparent in optimal lighting in ...