Synthetic aperture radar — (SAR) is a form of radar in which the highly directional (and thus very large) rotating antenna used by conventional radar is replaced with many low directivity small stationary antenna positions scattered over some area near or around the target … Wikipedia
Aperture synthesis — or synthesis imaging is a type of interferometry that mixes signals from a collection of telescopes to produce images having the same angular resolution as an instrument the size of the entire collection. At each separation and orientation, the… … Wikipedia
Sonar — This article is about underwater sound propagation. For atmospheric sounding, see SODAR. For other uses, see Sonar (disambiguation) … Wikipedia
Side-scan sonar — (also sometimes called side scan sonar, sidescan sonar, side looking sonar, side looking sonar and bottom classification sonar) is a category of sonar system that is used to create efficiently an image of large areas of the sea floor. This tool… … Wikipedia
Towed array sonar — A towed array sonar is a sonar array that is towed behind a submarine or surface ship. It is basically a long cable, up to 2000 m, with hydrophones that is trailed behind the ship when deployed.Fact|date=March 2008 The hydrophones are placed at… … Wikipedia
Marine mammals and sonar — A Humpback whale Active sonar, the transmission equipment used on some ships to assist with navigation, has been suggested[1] to be detrimental to the health and livelihood of some marine animals, although the precise mechanisms for this are not… … Wikipedia
Geophysical 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… … Wikipedia
Beamforming — is a signal processing technique used in sensor arrays for directional signal transmission or reception. This spatial selectivity is achieved by using adaptive or fixed receive/transmit beampattern. The improvement compared with an… … Wikipedia
Phased array — This article is about general theory and electromagnetic phased array. For the ultrasonic and medical imaging application, see phased array ultrasonics. In wave theory, a phased array is a group of antennas in which the relative phases of the… … Wikipedia
SAS — or SAS may refer to: Military * Special Air Service, the principal special forces unit of the British Army * Australian Special Air Service Regiment, Australian regiment derived from the British Army regiment * New Zealand Special Air Service (NZ … Wikipedia
