Radar is a detection system that uses radio waves to determine the range, angle, or velocity of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the object(s). Radio waves (pulsed or continuous) from the transmitter reflect off the object and return to the receiver, giving information about the object's location and speed.
radar stationradarsradar system
digital terrain modelDEMdigital elevation map
One powerful technique for generating digital elevation models is interferometric synthetic aperture radar where two passes of a radar satellite (such as RADARSAT-1 or TerraSAR-X or Cosmo SkyMed), or a single pass if the satellite is equipped with two antennas (like the SRTM instrumentation), collect sufficient data to generate a digital elevation map tens of kilometers on a side with a resolution of around ten meters.
RADARSAT-1 used a synthetic aperture radar (SAR) sensor to image the Earth at a single microwave frequency of 5.3 GHz, in the C band (wavelength of 5.6 cm). The SAR support structure was designed and manufactured by Northrop Grumman Astro Aerospace and deployed to 15 m in length on orbit. Unlike optical satellites that sense reflected sunlight, SAR systems transmitted microwave energy towards the surface and recorded the reflections. Thus, Radarsat-1 imaged the Earth, day or night, in any atmospheric condition, such as cloud cover, rain, snow, dust or haze. Each of RADARSAT-1's seven beam modes offered a different image resolution.
aperture synthesis imagingsynthetic apertureinterferometric imaging
Interferometric synthetic aperture radar (IfSAR or InSAR). Synthetic aperture radar (SAR) and Inverse synthetic aperture radar (ISAR). Synthetic aperture sonar. Beamforming. Synthetic aperture magnetometry. Light field. Development of radio interferometry, from Astronomical Optical Interferometry, A Literature Review by Bob Tubbs, Cambridge, 2002. Cambridge Optical Aperture Synthesis Telescope. APerture SYNthesis SIMulator (an interactive tool to learn the concepts of Aperture Synthesis).
phased array radarphased-arrayphased-array radar
Interferometric synthetic-aperture radar. Inverse synthetic-aperture radar. Multi-user MIMO. Optical heterodyne detection. Phased array ultrasonics. Phased-array optics. Radar MASINT. Side-scan sonar. Single-frequency network. Smart antenna. Synthetic-aperture radar. Synthetic aperture sonar. Synthetically thinned aperture radar. Thinned-array curse. Wave field synthesis. History of smart antennas. Radar Research and Development - Phased Array Radar—National Severe Storms Laboratory. Shipboard Phased Array Radars. NASA Report: MMICs For Multiple Scanning Beam Antennas for Space Applications. Principle of Phased Array @ www.radartutorial.eu. 'Phased Array' microphone system of Tony Faulkner.
In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats. It is thus the inverse of the spatial frequency. Wavelength is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings and is a characteristic of both traveling waves and standing waves, as well as other spatial wave patterns. Wavelength is commonly designated by the Greek letter lambda . The term wavelength is also sometimes applied to modulated waves, and to the sinusoidal envelopes of modulated waves or waves formed by interference of several sinusoids.
An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth, resulting from the sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in size from those that are so weak that they cannot be felt to those violent enough to toss people around and destroy whole cities. The seismicity, or seismic activity, of an area is the frequency, type and size of earthquakes experienced over a period of time. The word tremor is also used for non-earthquake seismic rumbling.
Next ESA SAR Toolbox for viewing, calibrating and analyzing ERS 1 & 2 SAR Level 1 data and higher.
Seasat Views Ocean and Sea Ice with Synthetic Aperture Radar. SEASAT II, JSR-83-203, March 1984. SEASAT III & IV, JSR-84-203, August 1984. ASF Seasat portal, June 2013. ASF about Seasat, June 2013. ASF Data Download, June 2013.
Flares come mainly from SAR-panels of the satellites. Although overshadowed by the Iridium satellites, the flares are often long-lasting, with the satellites traversing much of the sky at brighter-than-average magnitudes. *SAR Lupe, a system of five military SAR-satellites of Germany Two solar arrays for 3.8 kW at 42 V DC. Stabilization, navigation and GPS systems. Synthetic aperture radar working in X band. 300 Gbit on-board memory and 310 Mbit/s data-link with ground segments. Command Center:. 🇮🇹 Italy Centro Controllo e Pianificazione Missione del Fucino. Tracking and data stations:. 🇦🇷 Argentina Cordoba station. 🇸🇪 Sweden Kiruna station.
OPS 3762: The very first SAR radar in space, 1964. Seasat: The SAR radar in space in 1978. SAR Lupe: Germany's military radar satellites. SAR technology(Synthetic Aperture Radar). Earth observation technology. Earth observation satellite. Digital elevation model. SIR-A (Shuttle Imaging Radar) aboard STS-2 in 1981. SIR-B aboard STS-41-G in 1984. SRL-1 (Shuttle Radar Laboratory): SIR-C (Spaceborne Imaging Radar) and X-SAR (X-Band Synthetic Aperture Radar) on STS-59 in 1994. SRL-2: SIR-C/X-SAR on STS-68 in 1994. SRTM (Shuttle Radar Topography Mission) on STS-99 in 2000. Astrium Geo. TerraSAR-X at DLR website. TerraSAR-X for risk management. TanDEM-X at DLR website.
It provides multi temporal Synthetic Aperture Radar images with a temporal gap of 12 days. Data products can be used for SAR Interferometry applications. Data downloads can be done through sentinel data hub. Sentinel 2 mission outputs are also available in the same data hub. Sentinel-1A arrived at its launch site in Kourou, French Guiana on 25 February 2014, ahead of its launch which was at the time planned for 28 March. Sentinel-1A was launched on 3 April 2014 by a Soyuz rocket at 21:02:31 GMT (23:02:31 CEST). The first stage separated 118 seconds later, followed by the fairing (209 s), second stage (287 s) and the upper assembly (526 s).
For instance, Interferometric synthetic-aperture radar and aerial photo interpretation is the tool used in history for detecting surface deformation and updating landslide inventory respectively. GIS is also used to overlay layers of terrain (elevation and slope angle), lithology with rainfall data to generate landslide hazard maps. With the different weightings in respective parameters, the hazard could be zoned to get the risk controlled. Remote sensing has much potential in environmental applications.
remote sensingmulti-spectral aerial photographyremote-sensing
Synthetic Aperture Radar (SAR). INSAR - Interferometric SAR.
military orbital radarSatellite radarSpace Radar
German SAR-Lupe. Russian Kondor. Japanese Information Gathering Satellite. a synthetic aperture radar (SAR) for high-resolution imaging. a radar altimeter, to measure the ocean topography. a wind scatterometer to measure wind speed and direction. RISAT-1 (SAR,ISRO India, 2012). RORSAT (SAR, Soviet Union, 1967-1988). Seasat (SAR, altimeter, scatterometer, US, 1978). RADARSAT-1 (SAR, Canadian, 1995). RADARSAT-2 (SAR, Canadian, 2007). SAR Lupe 1-5 (SAR satellites of the German Air Force). TerraSAR-X (SAR Germany, 2007). TanDEM-X (SAR Germany, 2010). COSMO-SkyMed (SAR, Italy, 2007). SAOCOM (L band SAR constellation, Argentina). TecSAR (SAR, Israeli, 2008). TOPEX/Poseidon (altimeter).
Interferometric Synthetic Aperture Radar. Imagery Analysis. Imaging Science. Land cover. List of Earth observation satellites. Synthetic Aperture Radar.
During the mapping cycle 1 (left-looking) radar surface mapping on Venus (September 15, 1990 to May 15, 1991), around 70% of the Venusian surface was mapped by synthetic aperture radar. In cycle 2 (right-looking), 54.5% of the surface was mapped, mainly the south pole regions and gaps from cycle 1 during May 15, 1991 to January 14, 1992. Combining cycle 1 and 2 results in a total coverage of 96% of Venusian surface mapped. Cycle 3 (left looking) filled remaining gaps and collected stereo imagery of approximately 21.3% of the surface, increasing the total coverage to 98%. The use of Interferometric synthetic aperture radar (InSAR) for mapping Venus has been proposed.
Other technologies such as the T/R modules, the C-band synthetic-aperture radar antenna, the advanced data management and transmission subsystems, and the on-board computer, were developed in L'Aquila and Milan. The C-SAR instrument is the responsibility of Astrium Gmbh. The ground segment prime contractor is Astrium with subcontractors Telespazio, WERUM, Advanced Computer Systems and Aresys. Final test verification of the satellite was completed at Thales Alenia Space's clean rooms in Rome and Cannes. Examples of images produced from Sentinel-1 data. A single C-band synthetic-aperture radar (C-SAR) with its electronics.
Interferometric synthetic aperture radar (InSAR) is a radar technique used in geodesy and remote sensing. Satellite synthetic aperture radar images of a geographic feature are taken on separate days, and changes that have taken place between radar images taken on the separate days are recorded as fringes similar to those obtained in holographic interferometry. The technique can monitor centimeter- to millimeter-scale deformation resulting from earthquakes, volcanoes and landslides, and also has uses in structural engineering, in particular for the monitoring of subsidence and structural stability. Fig 20 shows Kilauea, an active volcano in Hawaii.
Interferometric synthetic aperture radar. Inverse synthetic aperture radar. List of telescope types. Synthetic aperture radar. Jan Hamann, Steen Hannestad, Martin S. Sloth, Yvonne Y. Y. Wong (2008), "Observing trans-Planckian ripples in the primordial power spectrum with future large scale structure probes", Journal of Cosmology and Astroparticle Physics, arxiv 0807.4528. Jonathan R. Pritchard, Elena Pierpaoli (2008), "Constraining massive neutrinos using cosmological 21 cm observations", Phys. Rev. D 78:065009,2008, arxiv 0805.1920. Yi Mao, Max Tegmark, Matthew McQuinn, Matias Zaldarriaga, Oliver Zahn (2008), "How accurately can 21 cm tomography constrain cosmology?", Phys. Rev.
remote-sensingremotely sensedremote sensor
Interferometric synthetic aperture radar is used to produce precise digital elevation models of large scale terrain (See RADARSAT, TerraSAR-X, Magellan). Laser and radar altimeters on satellites have provided a wide range of data. By measuring the bulges of water caused by gravity, they map features on the seafloor to a resolution of a mile or so. By measuring the height and wavelength of ocean waves, the altimeters measure wind speeds and direction, and surface ocean currents and directions. Ultrasound (acoustic) and radar tide gauges measure sea level, tides and wave direction in coastal and offshore tide gauges.