Related topics: nasa

Video: New radar mission for Europe

The upcoming Copernicus Radar Observation System for Europe in L-band (ROSE-L) will provide continuous day-and-night all-weather monitoring of Earth's land, oceans and ice, and offer frequent observations of Earth's surface ...

Animated maps reveal true level of devastation in Ukraine

Two years of war in Ukraine have caused widespread devastation to the country's citizenry, infrastructure and environment, and new research utilizing publicly accessible satellite imagery lays bare the scope of destruction.

Can astronomers use radar to spot a cataclysmic asteroid?

How can humans protect the Earth from "devastating asteroid and comet impacts?" According to the National Academies and their 2023-2032 Planetary Science and Astrobiology Decadal Survey, ground-based astronomical radar systems ...

Heritage ERS-2 satellite to reenter Earth's atmosphere

Throughout its 16-year working life, the second European Remote Sensing satellite, ERS-2, returned a wealth of information that revolutionized our perspective of our planet and understanding of climate change. As well as ...

A new map shows all above-ground biomass in the Brazilian Amazon

Publication of a new map showing all the above-ground biomass in the Brazilian Amazon is good news in the context of the severe crisis afflicting the world's largest contiguous tropical rainforest. Using airborne laser scanning ...

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Radar

Radar is an object detection system that uses electromagnetic waves to identify the range, altitude, direction, or speed of both moving and fixed objects such as aircraft, ships, motor vehicles, weather formations, and terrain. The term RADAR was coined in 1941 as an acronym for radio detection and ranging. The term has since entered the English language as a standard word, radar, losing the capitalization. Radar was originally called RDF (Radio Direction Finder, now used as a totally different device) in the United Kingdom.

A radar system has a transmitter that emits microwaves or radio waves. These waves are in phase when emitted, and when they come into contact with an object are scattered in all directions. The signal is thus partly reflected back and it has a slight change of wavelength (and thus frequency) if the target is moving. The receiver is usually, but not always, in the same location as the transmitter. Although the signal returned is usually very weak, the signal can be amplified through use of electronic techniques in the receiver and in the antenna configuration. This enables radar to detect objects at ranges where other emissions, such as sound or visible light, would be too weak to detect. Radar is used in meteorological detection of precipitation, measuring ocean surface waves, air traffic control, police detection of speeding traffic, and by the military.

This text uses material from Wikipedia, licensed under CC BY-SA