Atlantikwall Regelbau L487 Bertha - Night Fighter Bunker for Luftwaffe ...

Bunker L487 is a ww2 German bunker for radio measurement device evaluation for night fighter control "Bertha" in English.

A night fighter (also known as all-weather fighter or all-weather interceptor for a period of time after World War II) is a fighter aircraft adapted for use at night or in other times of bad visibility. Night fighters began to be used in World War I and included types that were specifically modified to operate at night.

During World War II, night fighters were either purpose-built night fighter designs, or more commonly, heavy fighters or light bombers adapted for the mission, often employing radar or other systems for providing some sort of detection capability in low visibility. Many WW II night fighters also included instrument landing systems for landing at night, as turning on the runway lights made runways into an easy target for opposing intruders. Some experiments tested the use of day fighters on night missions, but these tended to work only under very favorable circumstances and were not widely successful.

Avionics systems were greatly miniaturized over time, allowing the addition of radar altimeter, terrain-following radar, improved instrument landing system, microwave landing system, Doppler weather radar, LORAN receivers, GEE, TACAN, inertial navigation system, GPS, and GNSS in aircraft. The addition of greatly improved landing and navigation equipment combined with radar led to the use of the term all-weather fighter or all-weather fighter attack, depending on the aircraft capabilities. The use of the term night fighter gradually faded away as a result of these improvements making the vast majority of fighters capable of night operation.