A University of Alaska Fairbanks-led research team has developed a way to use satellite images to determine the amount of methane being released from northern lakes, a technique that could help climate change modelers better ...
Earth Sciences
May 11, 2020
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154
Physicists at the Institute of Science and Technology Austria (IST Austria) have invented a new radar prototype that uses quantum entanglement as a method of object detection. This successful integration of quantum mechanics ...
General Physics
May 08, 2020
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8065
The Arecibo Observatory in Puerto Rico is following an asteroid approaching Earth this week and while it poses no threat, it appears to know our planet is facing a pandemic.
Space Exploration
Apr 23, 2020
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52
Dr. Vishnu Nandan is a radar remote sensing expert on Arctic and Antarctic sea ice, and a post-doctoral researcher at the UM Centre for Earth Observation Science (CEOS). He has only recently returned from the High Arctic ...
Other
Apr 21, 2020
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1
The Copernicus Sentinel-1 mission takes us over part of the Mekong Delta—a major rice-producing region in southwest Vietnam.
Environment
Mar 30, 2020
0
13
A little over a year after landing, China's spacecraft Chang'E-4 is continuing to unveil secrets from the far side of the Moon. The latest study, published on Feb. 26 in Science Advances, reveals what lurks below the surface.
Space Exploration
Feb 26, 2020
5
1068
NASA has selected four Discovery Program investigations to develop concept studies for new missions. Although they're not official missions yet and some ultimately may not be chosen to move forward, the selections focus on ...
Space Exploration
Feb 14, 2020
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32
The US-European Solar Orbiter probe launches Sunday night from Florida on a voyage to deepen our understanding of the Sun and how it shapes the space weather that impacts technology back on Earth.
Space Exploration
Feb 09, 2020
0
63
The European Space Agency will embark upon one of its most ambitious projects to date Sunday when its Solar Orbiter probe launches from Florida's Cape Canaveral bound for the Sun.
Space Exploration
Feb 07, 2020
36
703
The last time NASA carried out an in-depth study of winter storms in the heavily populated Northeast, the Berlin Wall had just come down and George H.W. Bush occupied the White House.
Environment
Jan 24, 2020
0
12
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
