azimuth and elevation
21Pfund telescope — The Pfund telescope, originated by A. H. Pfund, provides another method for achieving a fixed telescope focal point in space regardless of where the telescope line of sight is pointed. This configuration utilizes a two axis feed flat mirror to… …
22Rangekeeper — Rangekeepers were electromechanical fire control computers used primarily during the early part of the 20th century. They were sophisticated analog computers whose development reached its zenith following World War II, specifically the Computer… …
23AN/FPS-17 — The AN/FPS 17 is a ground based fixed beam radar system that was installed at Pirinçlik Air Base in south eastern Turkey.This system was deployed to satisfy scientific and technical intelligence collection requirements during the Cold War. The… …
24History of radar — The history of radar starts with experiments by Heinrich Hertz in the late 19th century that showed that radio waves were reflected by metallic objects. This possibility was suggested in James Clerk Maxwell s seminal work on electromagnetism.… …
25Solar sail — Solar sails (also called light sails or photon sails, especially when they use light sources other than the Sun) are a proposed form of spacecraft propulsion using large membrane mirrors. Radiation pressure is about 10 5 Pa at Earth s distance… …
26telescope — /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… …
27Clutter (radar) — Clutter is a term used for unwanted echoes in electronic systems, particularly in reference to radars. Such echoes are typically returned from ground, sea, rain, animals/insects, chaff and atmospheric turbulences, and can cause serious… …
28Electro-optical MASINT — is a subdiscipline of Measurement and Signature Intelligence, (MASINT) and refers to intelligence gathering activities which bring together disparate elements that do not fit within the definitions of Signals Intelligence (SIGINT), Imagery… …
29Abhay IFV — Infobox Weapon name = Abhay caption = origin = flagcountry|India type = Infantry Combat Vehicle is artillery = is vehicle = yes service = used by = wars = designer = DRDO design date = manufacturer = Heavy Vehicles Factory, Avadi unit cost =… …
30Bearing (navigation) — This article is about the navigational term. For other uses, see Bearing. A standard Brunton Geo compass, used commonly by geologists and surveyors to obtain a bearing in the field. In marine navigation, a bearing is the direction one object is… …
