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Racemosa gas field
Racemosa gas field is an operating onshore natural gas field in Mexico, wholly owned and operated by PEMEX, whose associated gas and oil output began in 2021.
RACER (autonomous driving program)
RACER, Robotic Autonomy in Complex Environments with Resiliency, is a DARPA program begun in 2021 that lets unmanned ground vehicles drive fast off-road without GPS or human intervention.
Rachel Armstrong
Rachel Armstrong is a British applied scientist and sustainability innovator who works on living architecture, and is ZAP Professor of Regenerative Architecture at KU Leuven in Belgium.
Rachel Maines
Rachel P. Maines (born 1950) is an American historian of technology whose 1999 book The Technology of Orgasm originated the Victorian vibrator story, a claim a 2018 audit found unsupported.
Racing bicycle
A racing bicycle, or racing bike, is a lightweight bicycle with drop handlebars and narrow high-pressure tires, designed for speed on paved roads and shaped by road racing rules.
Racing Bulls VCARB 02
The Racing Bulls VCARB 02 is a Formula One car raced by Visa Cash App Racing Bulls in the 2025 season, with drivers Yuki Tsunoda and Isack Hadjar.
Racing Bulls VCARB 03
The Racing Bulls VCARB 03 is a Formula One car built by Visa Cash App Racing Bulls for the 2026 season, powered by the first Red Bull Ford engine.
Rack and pinion
A rack and pinion (rack & pinion) is a gear mechanism in which a rotating pinion meshes with a straight rack, converting rotary motion into linear motion or the reverse.
Rack railway
A rack railway, also called a cog railway, is a steep-grade railway where a toothed rack rail engaged by a gear gives traction and braking.
Rack unit
A rack unit (symbol U or RU) is the standard unit of vertical height for equipment in 19-inch racks, equal to 1.75 inches (44.45 mm), defined by the EIA-310 standard.
Racket (programming language)
Racket, formerly PLT Scheme, is a general-purpose, functional-first programming language, a Lisp dialect and Scheme descendant designed around building small problem-specific languages as easily as libraries.
Racon
A racon, from RAdar beaCON, is a receiver-transmitter beacon mounted on navigational marks such as buoys and lighthouses that, when triggered by a ship's radar, replies with a Morse-coded signal identifying the mark.
Radar
Radar, short for radio detection and ranging, is a sensing technique that transmits radio waves and measures reflections to find a target's distance and direction.
Radar altimeter
A radar altimeter, also called a radio altimeter, is an airborne instrument that measures an aircraft's height above the ground by timing radio signals reflected from the surface.
Radar astronomy
Radar astronomy is the active study of solar system objects by bouncing radio signals off them; its first planetary echo came from Venus in 1961.
Radar clutter
Radar clutter is the set of unwanted radar echoes, from the ground, sea, precipitation, chaff, and birds, that competes with the intended target and hinders detection.
Radar cross section
Radar cross section (RCS), also called radar signature, is a measure in square meters of how effectively a target reflects radar energy back to the radar.
Radar cross-section measurement
Radar cross-section measurement is an experimental technique that quantifies how strongly a target backscatters radar energy, expressed as an equivalent area in square meters, usually in dBsm.
Radar detector
A radar detector, also called a fuzz buster, is a passive radio receiver that alerts drivers to police speed-measuring radar on the X, K, and Ka bands.
Radar imaging
Radar imaging is a remote sensing technique using radio waves to form images of terrain, ocean, ice, and atmosphere, penetrating clouds and working at night where optical sensors cannot.
Radar jamming and deception
Radar jamming and deception are electronic warfare techniques that degrade enemy radar: jamming raises receiver noise to hide targets, while deception, including chaff and DRFM devices, injects false returns.
Radar speed gun
A radar speed gun is a Doppler radar device used by police to measure vehicle speed from a distance, first deployed in Glastonbury, Connecticut, in 1947.
RADARSAT
RADARSAT is a Canadian series of Earth observation satellites carrying synthetic aperture radar, which images day or night and through cloud, spanning RADARSAT-1 in 1995, RADARSAT-2 in 2007, and a three-satellite constellation launched in 2019.
Radek Zbořil
Radek Zbořil, born in 1973, is a Czech physical chemist and professor at Palacký University Olomouc, known as a pioneer of single-atom engineering and for work on nanomaterials.
Rademacher complexity
Rademacher complexity measures how well a class of functions can fit random noise, and enters generalization bounds relating a model's training error to its expected error on new data.
Radeon
Radeon, also known as ATI Radeon and AMD Radeon, is a brand of graphics cards and GPUs launched by ATI in 2000 and owned by AMD since 2006.
Radeon Pro
Radeon Pro, or AMD Radeon Pro, is AMD's brand of professional workstation graphics cards for CAD, digital content creation, rendering, and local AI inference, with certified drivers and ECC memory.
Radeon RX 480
The Radeon RX 480 is an AMD graphics card released on June 29, 2016, the first built on the Polaris architecture, pitched as the most affordable route to premium PC virtual reality.
Radeon RX 6000 series
The Radeon RX 6000 series is a family of AMD graphics cards built on the RDNA 2 architecture, announced in October 2020 with the flagship RX 6900 XT.
Radeon RX 9000 series
The Radeon RX 9000 series is a family of AMD desktop graphics cards built on RDNA 4, first sold in March 2025 with the RX 9070 XT.