frequency-sensitive detector
41telescope — /tel euh skohp /, n., adj., v., telescoped, telescoping. n. 1. an optical instrument for making distant objects appear larger and therefore nearer. One of the two principal forms (refracting telescope) consists essentially of an objective lens… …
42Gravitational wave — In physics, a gravitational wave is a fluctuation in the curvature of spacetime which propagates as a wave, traveling outward from a moving object or system of objects. Gravitational radiation is the energy transported by these waves. Important… …
43Geophysical MASINT — is a branch of Measurement and Signature Intelligence (MASINT) that involves phenomena transmitted through the earth (ground, water, atmosphere) and manmade structures including emitted or reflected sounds, pressure waves, vibrations, and… …
44Microphone — For the indie film, see Microphone (film). Microphones redirects here. For the indie band, see The Microphones. A …
45Burglar alarm — Silent alarm redirects here. For the album, see Silent Alarm (album). Burglar (or intrusion), fire and safety alarms are all electronic today. Sensors are connected to a control unit via a low voltage hardwire or narrowband RF signal which is… …
46Ultraviolet — UV redirects here. For other uses, see UV (disambiguation). UVB redirects here. For the mysterious shortwave radio station in Russia, see UVB 76. For other uses, see Ultraviolet (disambiguation). False color image of the Sun s corona as seen in… …
47electromagnetic radiation — Physics. radiation consisting of electromagnetic waves, including radio waves, infrared, visible light, ultraviolet, x rays, and gamma rays. [1950 55] * * * Energy propagated through free space or through a material medium in the form of… …
48List of vacuum tubes — This is a list of vacuum tubes or thermionic valves. Before the advent of semiconductor devices, hundreds of tube types were used in consumer and industrial electronics; today only a few types are still used in specialized applications. Contents… …
49Optical heterodyne detection — is an important special case of heterodyne detection. In heterodyne detection, a signal of interest at some frequency is non linearly mixed with a reference local oscillator (LO) that is set at a close by frequency. The desired outcome is the… …
50mass spectrometry — or mass spectroscopy Analytic technique by which chemical substances are identified by sorting gaseous ions by mass using electric and magnetic fields. A mass spectrometer uses electrical means to detect the sorted ions, while a mass spectrograph …
