Explore topic-wise fullforms in Space Science

INFO: Full form for QVL is Qualified Vendors List in Space Science category
QVL also has other full forms in other categories mentioned below.

INFO: Full form for QVL is Quality Verification Listing in Space Science category
QVL also has other full forms in other categories mentioned below.

INFO: Full form for IMAX is Shuttle Cabin Camera (manufactured By Imax, Inc.) in Space Science category
IMAX also has other full forms in other categories mentioned below.

INFO: Full form for DF is Development Flight in Space Science category
DF also has other full forms in other categories mentioned below.

Direction finding (DF), or radio direction finding (RDF), is the measurement of the direction from which a received signal was transmitted. This can refer to radio or other forms of wireless communication, including radar signals detection and monitoring (ELINT/ESM). By combining the direction information from two or more suitably spaced receivers (or a single mobile receiver), the source of a transmission may be located via triangulation. Radio direction finding is used in the navigation of ships and aircraft, to locate emergency transmitters for search and rescue, for tracking wildlife, and to locate illegal or interfering transmitters. RDF was important in combating German threats during both the World War II Battle of Britain and the long running Battle of the Atlantic. In the former, the Air Ministry also used RDF to locate its own fighter groups and vector them to detected German raids.

RDF systems can be used with any radio source, although very long wavelengths (low frequencies) require very large antennas, and are generally used only on ground-based systems. These wavelengths are nevertheless used for marine radio navigation as they can travel very long distances "over the horizon", which is valuable for ships when the line-of-sight may be only a few tens of kilometres. For aerial use, where the horizon may extend to hundreds of kilometres, higher frequencies can be used, allowing the use of much smaller antennas. An automatic direction finder, which could be tuned to radio beacons called non-directional beacons or commercial AM radio broadcasters, was until recently, a feature of most aircraft, but is now being phased out

For the military, RDF is a key tool of signals intelligence. The ability to locate the position of an enemy transmitter has been invaluable since World War I, and played a key role in World War II's Battle of the Atlantic. It is estimated that the UK's advanced "huff-duff" systems were directly or indirectly responsible for 24% of all U-boats sunk during the war. Modern systems often used phased array antennas to allow rapid beamforming for highly accurate results, and are part of a larger electronic warfare suite.

Early radio direction finders used mechanically rotated antennas that compared signal strengths, and several electronic versions of the same concept followed. Modern systems use the comparison of phase or doppler techniques which are generally simpler to automate. Early British radar sets were referred to as RDF, which is often stated was a deception. In fact, the Chain Home systems used large RDF receivers to determine directions. Later radar systems generally used a single antenna for broadcast and reception, and determined direction from the direction the antenna was facing.

INFO: Full form for DF is Disassembly Facility in Space Science category
DF also has other full forms in other categories mentioned below.

INFO: Full form for DF is Development Forward in Space Science category
DF also has other full forms in other categories mentioned below.

INFO: Full form for DF is Display Function in Space Science category
DF also has other full forms in other categories mentioned below.

INFO: Full form for PB is Phonetically Balanced in Space Science category
PB also has other full forms in other categories mentioned below.

INFO: Full form for PB is Pre-burner in Space Science category
PB also has other full forms in other categories mentioned below.

A push-button (also spelled pushbutton) or simply button is a simple switch mechanism to control some aspect of a machine or a process. Buttons are typically made out of hard material, usually plastic or metal. The surface is usually flat or shaped to accommodate the human finger or hand, so as to be easily depressed or pushed. Buttons are most often biased switches, although many un-biased buttons (due to their physical nature) still require a spring to return to their un-pushed state.Terms for the "pushing" of a button include pressing, depressing, mashing, slapping, hitting, and punching.

Playback may refer to:

The crawler-transporters, formally known as the Missile Crawler Transporter Facilities, are a pair of tracked vehicles used to transport spacecraft from NASA's Vehicle Assembly Building (VAB) along the Crawlerway to Launch Complex 39. They were originally used to transport the Saturn IB and Saturn V rockets during the Apollo, Skylab and Apollo–Soyuz programs. They were then used to transport Space Shuttles from 1981 to 2011. The crawler-transporters carry vehicles on the mobile launcher platforms used by NASA, and after each launch return to the pad to take the platform back to the VAB.

The two crawler-transporters were designed and built by Marion Power Shovel Company using components designed and built by Rockwell International at a cost of US$14 million each. Upon its construction, the crawler-transporter became the largest self-powered land vehicle in the world. While other vehicles such as bucket-wheel excavators like Bagger 293, dragline excavators like Big Muskie and power shovels like The Captain are significantly larger, they are powered by external sources.

The two crawler-transporters were added to the National Register of Historic Places on January 21, 2000.