The Telescope Array project is an international collaboration involving research and educational institutions in Japan, The United States, Russia, South Korea, and Belgium. The experiment is designed to observe air showers induced by ultra-high-energy cosmic ray using a combination of ground array and air-fluorescence techniques. It is located in the high desert in Millard County , Utah , United States, at about 1,400 meters (4,600 ft) above sea level.
29-506: The Telescope Array observatory is a hybrid detector system consisting of both an array of 507 scintillation surface detectors (SD) which measure the distribution of charged particles at the Earth's surface, and three fluorescence stations which observe the night sky above the SD array. Each fluorescence station is also accompanied by a LIDAR system for atmospheric monitoring. The SD array is much like that of
58-472: A conventional radar in which the transmitter and receiver are co-located is called a monostatic radar . A system containing multiple spatially diverse monostatic or bistatic radar components with a shared area of coverage is called multistatic radar . Many long-range air-to-air and surface-to-air missile systems use semi-active radar homing , which is a form of bistatic radar. Some radar systems may have separate transmit and receive antennas, but if
87-479: A cosmic ray air shower. The stations are positioned on a triangle about 35 km apart from one another with the Central Laser Facility close to the triangle's center. Each of the three stations has 12–14 telescopes viewing the range from 3°–33° elevation . The three sites are named Black Rock Mesa (BRM), Long Ridge (LR), and Middle Drum (MD). By combining the data from the three sites, it
116-435: A fence-like configuration, detecting targets which pass between the transmitter and receiver, with the bistatic angle near 180 degrees. This is a special case of bistatic radar, known as a forward scatter radar , after the mechanism by which the transmitted energy is scattered by the target. In forward scatter , the scattering can be modeled using Babinet's principle and is a potential countermeasure to stealth aircraft as
145-649: A new visitor center was opened at the Cosmic Ray Center. It features displays about the history of cosmic ray research in Utah and about the Telescope Array, which is spread across the desert west of Delta. The center also includes a display about the nearby Topaz internment camp, where U.S. citizens of Japanese descent were imprisoned during World War II. TALE is the Telescope Array Low Energy extension. It
174-465: A power supply, two layers of scintillation detectors and electronics. Power is generated by a 120W solar panel and stored in a sealed lead-acid battery. The system has the capacity to operate for one week in complete darkness. Each scintillation detector layer is made of extruded plastic scintillator that is 1.2 cm thick and has an area of 3m. Download coordinates as: The Telescope Array has three fluorescence detector (FD) telescope stations. As in
203-425: A radar or sonar system with a separated transmitter and receiver. The Doppler shift is due to the component of motion of the object in the direction of the transmitter, plus the component of motion of the object in the direction of the receiver. Equivalently, it can be considered as proportional to the bistatic range rate . In a bistatic radar with wavelength λ , where the distance between transmitter and target
232-403: A specific observatory, telescope or astronomical instrument is a stub . You can help Misplaced Pages by expanding it . This particle physics –related article is a stub . You can help Misplaced Pages by expanding it . Bistatic radar Bistatic radar is a radar system comprising a transmitter and receiver that are separated by a distance comparable to the expected target distance. Conversely,
261-473: Is R tx and distance between receiver and target is R rx , the received bistatic Doppler frequency shift is calculated as: Note that objects moving along the line connecting the transmitter and receiver will always have 0 Hz Doppler shift, as will objects moving around an ellipse of constant bistatic range. Bistatic imaging is a radar imaging technique using bistatic radar (two radar instruments, with one emitting and one receiving). The result
290-457: Is able to maintain a 24-hour duty cycle at a fraction of the cost of conventional detection systems. In September 2012, the W. M. Keck Foundation awarded researchers at the University of Utah a $ 1 million grant to develop a bistatic radar detection system. This system will be built alongside the existing Telescope Array and will use analog television transmitters and digital receivers to observe
319-472: Is an effort to overcome some of the problems inherent to current cosmic ray detection techniques. Due to sun, moon and weather, fluorescence telescopes are usually limited to a ten percent duty cycle. Ground arrays can run during the day, but require a large amount of land, making it necessary to build them in remote locations. The goal of the TARA Project is to develop a bistatic radar detection system that
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#1733086031575348-456: Is designed to observe cosmic rays with energies between 3×10eV and 10eV. TALE adds 10 new telescopes to the Middle Drum observatory site (24 total telescopes) extending the vertical field of view so that it now extends from 3 to 59 degrees in elevation. This allows the station to see the shower development including shower maximum for lower energy events. This is critical when trying to determine
377-564: Is possible to determine the primary energy, the arrival direction, and the maximum point of longitudinal development for an air shower. The Lon and Mary Watson Millard County Cosmic Ray Center was dedicated on March 20, 2006. The center is located at 648 West Main Street in Delta. The building serves as a headquarters and data processing center for the Telescope Array Project. In October 2011,
406-510: Is termed a passive coherent location system or passive covert radar . Any radar which does not send active electro-magnetic pulse is known as passive radar. Passive coherent location also known as PCL is a special type of passive radar, which exploits the transmitters of opportunity especially the commercial signals in the environment. The principal advantages of bistatic and multistatic radar include: The principal disadvantages of bistatic and multistatic radar include: The bistatic angle
435-399: Is the angle subtended between the transmitter, target and receiver in a bistatic radar. When it is exactly zero the radar is a monostatic radar , when it is close to zero the radar is pseudo-monostatic, and when it is close to 180 degrees the radar is a forward scatter radar. Elsewhere, the radar is simply described as a bistatic radar. The bistatic angle is an important factor in determining
464-466: The AGASA group, but covers an area that is nine times larger. The hybrid setup of the Telescope Array project allows for simultaneous observation of both the longitudinal development and the lateral distribution of the air showers. When a cosmic ray passes through the Earth's atmosphere and triggers an air shower , the fluorescence telescopes measure the scintillation light generated as the shower passes through
493-600: The University of Utah . The Telescope Array , a merger of the AGASA and High Resolution Fly's Eye (HiRes) groups, and the Pierre Auger Observatory have improved on the results from AGASA by building larger, hybrid detectors and collecting greater quantities of more precise data. 35°47′13″N 138°28′34″E / 35.786966°N 138.47625°E / 35.786966; 138.47625 This article about
522-529: The radar cross section (RCS) is determined solely by the silhouette of the aircraft seen by the transmitter, and is unaffected by stealth coatings or shapings. The RCS in this mode is calculated as σ=4πA²/λ², where A is the silhouette area and λ is the radar wavelength. However, target may vary from place to place location and tracking is very challenging in forward scatter radars, as the information content in measurements of range, bearing and Doppler becomes very low (all these parameters tend to zero, regardless of
551-406: The radar cross section of the target. Bistatic range refers to the basic measurement of range made by a radar or sonar system with separated transmitter and receiver. The receiver measures the time difference of arrival of the signal from the transmitter directly, and via reflection from the target. This defines an ellipse of constant bistatic range, called an iso-range contour, on which
580-562: The angle subtended between transmitter, target and receiver (the bistatic angle ) is close to zero, then they would still be regarded as monostatic or pseudo-monostatic . For example, some very long range HF radar systems may have a transmitter and receiver which are separated by a few tens of kilometres for electrical isolation, but as the expected target range is of the order 1000–3500 km, they are not considered to be truly bistatic and are referred to as pseudo-monostatic. In some configurations, bistatic radars may be designed to operate in
609-461: The chemical composition of the incident cosmic ray particle. The TALE project also has a graded infill array of scintillator stations spaced 400m and 600m apart. It then connects to the main Telescope Array scintillator array where the scintillator detectors are 1200m apart. These stations measure charged particle densities (the shower footprint) at the Earth's surface for lower energy events approaching 3x10eV The Telescope Array RADAR (TARA) Project
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#1733086031575638-449: The gas of the atmosphere, while the array of scintillator surface detectors samples the footprint of the shower when it reaches the Earth's surface. At the center of the ground array is the Central Laser Facility which is used for atmospheric monitoring and calibrations. The surface detectors that make up the ground array are activated when ionizing particles from an extensive air shower pass through them. When these particles pass through
667-500: The location of the target in the fence). A multistatic radar system is one in which there are at least three components - for example, one receiver and two transmitters, or two receivers and one transmitter, or multiple receivers and multiple transmitters. It is a generalisation of the bistatic radar system, with one or more receivers processing returns from one or more geographically separated transmitter. A bistatic or multistatic radar that exploits non-radar transmitters of opportunity
696-516: The plastic scintillator within the detector, it induces scintillation photons to be emitted which are then gathered by 96 wavelength-shifting fibers and sent to photomultiplier tubes. The electronic components within the detectors then filter the results, giving the detectors comparable accuracy to the AGASA experiment. The surface detectors are evenly distributed across a 762 km grid array with 1.2 km between each unit. Each surface detector has an assembled weight of 250 kg and consists of
725-417: The previous Fly's Eye and High Resolution Fly's Eye (HiRes) experiments, these detectors work by measuring the air fluorescence light emitted by an extensive air shower . Each FD telescope consists of a primary mirror (made up of 18 smaller hexagonal mirror segments) and a camera. The cameras are made up of 256 photomultiplier tubes (PMTs) which are sensitive to the ultraviolet light generated by
754-520: The range, direction and strength of cosmic rays in order to trace them back to their point of origin. Once completed, this new facility will be known as the W.M. Keck Radar Observatory AGASA The Akeno Giant Air Shower Array ( AGASA ) was an array of particle detectors designed to study the origin of ultra-high-energy cosmic rays . It was deployed from 1987 to 1991 and decommissioned in 2004. It consisted of 111 scintillation detectors and 27 muon detectors spread over an area of 100 km . It
783-462: The target lies, with foci centred on the transmitter and receiver. If the target is at range R rx from the receiver and range R tx from the transmitter, and the receiver and transmitter are a distance L apart, then the bistatic range is R rx + R tx - L . Motion of the target causes a rate of change of bistatic range, which results in bistatic Doppler shift . Generally speaking, constant bistatic range points draw an ellipsoid with
812-455: The transmitter and receiver positions as the focal points. The bistatic iso-range contours are where the ground slices the ellipsoid. When the ground is flat, this intercept forms an ellipse. Note that except when the two platforms have equal altitude, these ellipses are not centered on the specular point. Bistatic Doppler shift is a specific example of the Doppler effect that is observed by
841-564: Was operated by the Institute for Cosmic Ray Research , University of Tokyo at the Akeno Observatory . The results from AGASA were used to calculate the energy spectrum and anisotropy of cosmic rays. The results helped to confirm the existence of ultra-high energy cosmic rays ( > 5 × 10 eV ), such as the so-called " Oh-My-God " particle that was observed by the Fly's Eye experiment run by
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