To help avoid collision with terrain ( CFIT ), aircraft use systems such as ground-proximity warning systems ( GPWS ), which use radar altimeters as a key element.

When the bomb reached the design height for this stage ( reportedly 2, 000 meters ) the membrane closed a circuit, activating the circuit between the radar altimeters and the projectile gun.

* Two or more redundant radar altimeters were used to reliably detect descent.

Some of these make the use of radar altimeters possible.

This technique can be used in continuous wave radar and is often found in aircraft radar altimeters.

A number of satellites ( see links ) use advanced dual-band radar altimeters to measure height from a spacecraft.

Spaceborne radar altimeters have proven to be superb tools for mapping ocean-surface topography, the hills and valleys of the sea surface.

* Laser and radar altimeters on satellites have provided a wide range of data.

Also, some free-fall nuclear weapons, such as the British Yellow Sun and Blue Danube, used RATs to power radar altimeters and firing circuits ; these were a more reliable alternative to batteries.

* radar and laser altimeters

It is the most accurate technique currently available to determine the geocentric position of an Earth satellite, allowing for the precise calibration of radar altimeters and separation of long-term instrumentation drift from secular changes in ocean topography.

Major deficiencies with Blue Danube included the use of unreliable lead-acid accumulators to supply power to the firing circuits and radar altimeters.

At ground control the radar altimeters also have stopped-on readings of 102, 800 feet, the figure that we later agree upon as the more reliable.

It is the most accurate technique currently available to determine the geocentric position of an Earth satellite, allowing for the precise calibration of radar altimeters and separation of long-term instrumentation drift from secular changes in ocean surface topography.

A number of satellites ( See links ) use exotic dual-band radar altimeters to measure height from a spacecraft.

Sometimes they just parked at the side of the road and used radar on the trucks as they passed.

When surface to air missiles became capable of hitting high flying aircraft bombers, bombers used flight at low altitude to evade radar detection.

* Band ( radio ), a range of frequencies or wavelengths used in radio transmission and radar

* Conical scanning, a system used in early radar units to improve their accuracy

Instead, this effort evolved into the SAGE system for the US Air Force, which used large screens and light guns to allow operators to interact with radar data stored in the computer.

According to the limited information available, they used it to process radar cross section data for the Lockheed A-12 reconnaissance aircraft.

These double-balanced mixers are very widely used in microwave communication systems, satellite communication systems, and ultrahigh frequency ( UHF ) communications transmitters and receivers, and in radar systems transmitters and receivers.

Frequency modulation is also used in telemetry, radar, seismic prospecting and newborn EEG seizure monitoring.

Geophysical techniques used for subsurface exploration include measurement of seismic waves ( pressure, shear, and Rayleigh waves ), surface-wave methods and / or downhole methods, and electromagnetic surveys ( magnetometer, resistivity, and ground-penetrating radar ).

In the early 1980s a group of researchers interested in the history of Iram used NASA remote sensing satellites, ground penetrating radar, Landsat program data and images taken from the Space Shuttle Challenger as well as SPOT data to identify old camel train routes and points where they converged.

On 10 September 2007, Professor Stephen Harding of the University of Nottingham, used ground penetrating radar ( GPR ) equipment to pinpoint the location of a 1, 000-year-old Viking transport longship ( Nordic clinker design ) beneath 6 – 10 feet ( 2 – 3 meters ) of clay in Meols, Wirral, ( a well-known settling place of Vikings ).

At present, cavity magnetrons are commonly used in microwave ovens and in various radar applications.

The cavity magnetron was widely used during World War II in microwave radar equipment and is often credited with giving Allied radar a considerable performance advantage over German and Japanese radars, thus directly influencing the outcome of the war.

In late 1941, the Telecommunications Research Establishment in Great Britain used the magnetron to develop a revolutionary airborne, ground-mapping radar codenamed H2S.

As an approximation, the designers of radar systems for ballistic missiles, cruise missile, and antiship missiles used by the navies of NATO use as their equivalent of a nautical mile.

Parabolic mirrors are used in most modern reflecting telescopes and in satellite dishes and radar receivers.

The low-yield warheads were apparently selected to make the weapon unsuitable as a first-strike weapon against hardened targets in the Soviet Union, but could be used in a retaliatory strike against soft targets, or in a pre-emptive strike against unhardened surface targets such as airfields, SAM sites, radar sites and other similar targets, opening a pathway for heavy bombers.

These weapons are typically used to strike critical, vulnerable targets such as computerized command and control vehicles, radio trucks, radar antennae, vehicle engine blocks and the jet engines of enemy aircraft.

A long-range radar antenna ( electronics ) | antenna, known as ALTAIR, used to detect and track space objects in conjunction with anti-ballistic missile | ABM testing at the Ronald Reagan Ballistic Missile Defense Test Site | Ronald Reagan Test Site on Kwajalein Atoll.

Israeli military radar is typical of the type of radar used for air traffic control.

Serious investigation began eight years later after the discovery that radar could be used to track airplanes.

The Command offices were in the border country, up north, where the radar systems centralized their intelligence reports, and the fighters were dispatched to harry the enemy.

These were joined by radar in World War II.

Papers from a recent Rabbinical Assembly conference on theology were printed in a special issue of the journal Conservative Judaism ( Winter 1999 ); the editors note that Kaplan's naturalism seems to have dropped from the movement's radar screen.

They were fitted with new anti-aircraft guns, radar, and forward-launched ASW weapons, in addition to their existing light guns, depth charges, and torpedoes.

These vessels were significantly larger than wartime ships and had fully automatic main guns, unit Machinery, radar, sonar, and antisubmarine weapons such as the Squid mortar.

Their radar did not work, aviation was virtually non-existent and communications were not fully operational.

Most fighters up to this point had one engine but a number of twin engined fighters were built, however they were found defenseless against single engine fighters and were relegated to other tasks, some becoming night fighters, fitted with very primitive radar sets.

Featured were local gig reviews and articles that were below the radar of the mainstream music press.

NADGE / AEGIS were complemented, in West Germany by the German Air Defence Ground Environment ( GEADGE ), an updated radar network adding southern West Germany to the European system, and Coastal Radar Integration System ( CRIS ), adding data links from Danish coastal radars.

His contributions to electronic communications and radar were of vital importance in winning World War II.

The planes were forced to navigate and bomb entirely by radar.

Forces from the United States Air Force were added to provide radar monitoring, fighter intercept, in-flight refueling, and aerial / marine rescue.

Merchant shippers lacked modern radar and weather forecasting, so vessels were often caught up in intense gales:

Researchers were involved in efforts to develop computers, radar, and inertial guidance in connection with defense research during World War II and the Cold War.

In electronics, magnetic core memory, radar, single electron transistors, and inertial guidance controls were invented or substantially developed by MIT researchers.

In March 1990 two radar equipped Dornier / HAL Do 228-101s were ordered to form a maritime surveillance element by July 1991.

While they were directed back to him he disappeared from radar near Staraya Russa.

The British were the first to fully exploit radar as a defence against aircraft attack.