At times, this interferes with the Flagpole Glitch, nulling its effect, which means there's no reason for a speedrunner to risk messing up an attempt.
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Passive feed-through nulling is not used with CW radar altimeters because this eliminates the ground-bounce signal.
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The generalization from subspaces to subsystems formed a foundation for combining most known decoherence prevention and nulling strategies.
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Feed-through nulling significantly reduces the bleed-through signal, which can be used to increase receiver sensitivity in continuous wave radar.
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The nulling broadening algorithms can solve such problems hereinabove and avoid the additional complexity of the adaptive weight vector continuously updating.
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There has been a nuller built by the Jet Propulsion Laboratory that has flown on a NASA sounding rocket twice, once in 2011 and a second time in 2015. There is also a laboratory nuller at NASA Goddard Space Flight Center known as the Visible Nulling Coronagraph (VNC) that is actively conducting experiments. The Visible Nulling Coronagraph (VNC) experimental breadboard at NASA Goddard Space Flight Center.
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The upgraded telescope has been used for observing pulse nulling. The interferometer can be used at Channel 37 (608 MHz to 614 MHz, important radio astronomy frequencies) with lesser performance.
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Nulling interferometry is a type of interferometry in which two or more signals are mixed to produce observational regions in which the incoming signals cancel themselves out. This creates a set of virtual "blind spots" which prevent unwanted signals from those areas from interfering with weaker nearby signals. In 1978 Australian-American astronomer Ronald N. Bracewell suggested using nulling interferometry to search for planets around other stars. This technique was considered for use by both the Terrestrial Planet Finder (a canceled NASA mission) and Darwin (a canceled ESA mission).
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In ellipsometry, the film under investigation is placed onto a reflective substrate. The film and the substrate have different refractive indexes. In order to obtain data about film thickness, the light reflecting off of the substrate must be nulled. Nulling is achieved by adjusting the analyzer and polarizer so that all reflected light off of the substrate is extinguished.
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Temperature drift and device mismatches are the major causes of offset errors, and circuits employing direct coupling often integrate offset nulling mechanisms. Some circuits (like power amplifiers) even use coupling capacitors--except that these are present only at the input (and/or output) of the whole system but not between the individual circuit units inside the system.
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Ellipsometry can also be done as imaging ellipsometry by using a CCD camera as a detector. This provides a real time contrast image of the sample, which provides information about film thickness and refractive index. Advanced imaging ellipsometer technology operates on the principle of classical null ellipsometry and real-time ellipsometric contrast imaging. Imaging ellipsometry is based on the concept of nulling.
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Thus, no current will flow into the buffer's input (or equivalently no voltage will be present at the buffer's input). In practice, due to device mismatches the collector currents are unequal and this results in the difference flowing into the buffer's input resulting in an offset at its output. This is corrected by adjusting the input bias or adding offset nulling circuitry.
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PEGASE is a design for a space observatory developed by France in the early 2000s.Pegase: a space-based nulling interferometer It combined formation flying with infrared telescopes operating as a double-aperture interferometer. Three free-flying satellites would operate together;a beam combiner and two siderostats. The baseline of the interferometer would be adjustable to between 50 and 500 meters.
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ZF precoding aims at nulling the inter- user interference, at the expense of losing some signal gain. ZF precoding can achieve a performance close to the sum capacity when the number of users is large or the system is interference-limited (i.e., the noise is weak compared to the interference). A balance between MRT and ZF is obtained by the so- called regularized zero-forcingB.
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The Keck Interferometer (KI) connects the two 10-meter Keck telescopes as an infrared interferometer with a baseline of 85 meters. This project was funded by NASA and developed by the Jet Propulsion Laboratory, the W.M. Keck Observatory and NExScI. KI included the visibility amplitude and nulling modes as well as a more recently developed astrometric mode. During KI operations, scientists at NExScI provided support to plan and conduct observations.
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Two of the main types of smart antennas include switched beam smart antennas and adaptive array smart antennas. Switched beam systems have several available fixed beam patterns. A decision is made as to which beam to access, at any given point in time, based upon the requirements of the system. Adaptive arrays allow the antenna to steer the beam to any direction of interest while simultaneously nulling interfering signals.
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The platform is stabilized by three gyros mounted on it. One measured any rotations about the X axis, one about the Y, and one about the Z axis. They generated signals that were shaped in feedback circuits and sent back to torquers on the inner, middle and outer gimbals that exactly countered the rotations, nulling the gyro outputs and keeping the platform stable. The inner gimbal also carries three accelerometers, two pendulums, and a pair of prisms.
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Specially shaped directional antennas can increase the range of a Wi-Fi transmission without a drastic increase in transmission power. High gain antenna may be of many designs, but all allow transmitting a narrow signal beam over greater distance than a non-directional antenna, often nulling out nearby interference sources. Such "WokFi" techniques typically yield gains more than 10 dB over the bare system; enough for line of sight (LOS) ranges of several kilometers and improvements in marginal locations.
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Character scrambling or masking out of certain fields is also another simplistic yet very effective method of preventing sensitive information to be viewed. It is really an extension of the previous method of nulling out, but there is a greater emphasis on keeping the data real and not fully masked all together. This is commonly applied to credit card data in production systems. For instance, an operator at a call centre might bill an item to a customer's credit card.
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However, in the infrared, the difference is less by a few orders of magnitude. According to a 2000 ESA bulletin, all spacecraft components in the optical path would have to be passively cooled to 40 kelvins to allow infrared observations to take place. The planet search would have used a nulling interferometer configuration. In this system, phase shifts would be introduced into the three beams, so that light from the central star would suffer destructive interference and cancel itself out.
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In such a system, besides classic flight controls, many autopilots incorporate thrust control capabilities that can control throttles to optimize the airspeed. The autopilot in a modern large aircraft typically reads its position and the aircraft's attitude from an inertial guidance system. Inertial guidance systems accumulate errors over time. They will incorporate error reduction systems such as the carousel system that rotates once a minute so that any errors are dissipated in different directions and have an overall nulling effect.
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The joshiki-maku is a large, low hanging curtain hanging off of a ledge called the san-n-tesuri. It is used to separate the area where the audience is sitting from the main stage. The puppeteers stood behind the joshiki-maku, holding their puppets above the curtain while being hidden from the audience. However, the dezukai practice established later in the Bunraku form would let the actors be seen on stage moving with the puppets, nulling the use of the curtains.
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A map of this nulling DC potential versus the lateral position coordinate therefore produces an image of the work function of the surface. A related technique, electrostatic force microscopy (EFM), directly measures the force produced on a charged tip by the electric field emanating from the surface. EFM operates much like magnetic force microscopy in that the frequency shift or amplitude change of the cantilever oscillation is used to detect the electric field. However, EFM is much more sensitive to topographic artifacts than KPFM.
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Originally installed on Keck II, in January, 2012 OSIRIS was moved to the Keck 1 telescope. ; Keck Interferometer : The Interferometer allowed the light from both Keck telescopes to be combined into an baseline, near infrared, optical interferometer. This long baseline gave the interferometer an effective angular resolution of 5 milliarcseconds (mas) at 2.2 µm, and 24 mas at 10 µm. Several back-end instruments allowed the interferometer to operate in a variety of modes, operating in H, K, and L-band near infrared, as well as nulling interferometry.
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The discoverers argue that if the source is further than 70 parsecs away, its high brightness temperature would require it to be powered by a coherent emission process. (If within 70 parsecs, the source could be either coherent or incoherent.) They also claim that most known coherent emission processes are unlikely explanations for the source. Models proposed by others include a nulling pulsar, a pair of orbiting neutron stars,Is the Bursting Radio Source GCRT J1745-3009 a Double Neutron Star Binary?, R. Turolla, A. Possenti and A. Treves, Astrophysical Journal 628, #1 (July 2005), pp. L49-L52.
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This phenomenon explains the Italian influence on the English style of woodwork that dominates the mantelpiece. The most frequently occurring decorative elements are found in the wainscoting of the Rotherwas Room. Although the identities of the craftsmen are unknown, the figural carvings on the mantel bear similarity to contemporary works by the Huguenot sculptor Maximilian Colt at Robert Cecil, First Earl of Salisbury's Hatfield House, which dates from the same period. The polychrome engraved mantle of the Rotherwas Room bears a complex arrangement of figural representation and plant motifs, including: guilloche, cartouche motifs, decorative scrolls and foliage, gadroon nulling, and lozenges.
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The collecting area is two 8.4 meter aperture mirrors, which works out to about 111 m2 combined. This area is equivalent to an circular aperture, which would be greater than any other single telescope, but it is not comparable in many respects since the light is collected at a lower diffraction limit and is not combined in the same way. Also, an interferometric mode will be available, with a maximum baseline of for aperture synthesis imaging observations and a baseline of for nulling interferometry. This feature is along one axis with the LBTI instrument at wavelengths of 2.9–13 micrometres, which is the near infrared.
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Beamforming is the method used to create the radiation pattern of the antenna array by adding constructively the phases of the signals in the direction of the targets/mobiles desired, and nulling the pattern of the targets/mobiles that are undesired/interfering targets. This can be done with a simple Finite Impulse Response (FIR) tapped delay line filter. The weights of the FIR filter may also be changed adaptively, and used to provide optimal beamforming, in the sense that it reduces the Minimum Mean Square Error between the desired and actual beampattern formed. Typical algorithms are the steepest descent, and Least Mean Squares algorithms.
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The launch of Explorer 1 by the United States in 1958 suggested another application: space-based radar systems for detecting and tracking aircraft, ships, armored vehicles, ballistic missiles, and cruise missiles. These systems required the development of special techniques for canceling the radar clutter seen from space, nulling ground-based jammers, and compensating for Doppler shifts experienced by fast-moving satellites. Space-based radar systems spurred the development of smaller, lighter weight, and less costly components: monolithic microwave integrated circuits (MMICs) for operation at frequencies in the 1 GHz to 30 GHz (microwave) and 30 GHz to 300 GHz (millimeter wave) ranges. The high power levels needed for detection are easier to achieve at microwave frequencies.
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The remaining signal was measured as an AC voltage, and thus allowed for the manual calculation of total noise and distortion to approximately 0.1% minimum. Subsequent products from HP, Wandell & Goltermann, Radford, Marconi, Sound Technology, and Amber continued to refine measurement capabilities from the 1950s through the 1970s, but the model of usage remained relatively constant; signal generators and analyzers were separate pieces of equipment, and testing involved careful tuning of each one by a person with high technical skills. This changed in 1980 with the introduction of the Tektronix AA501 Distortion Analyzer, which automated the processes of setting levels, frequency tuning and nulling. At this same time Hewlett-Packard introduced the popular HP8903B, which combined a high quality signal generator and analyzer in a single unit.
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Smart antennas (also known as adaptive array antennas, digital antenna arrays, multiple antennas and, recently, MIMO) are antenna arrays with smart signal processing algorithms used to identify spatial signal signatures such as the direction of arrival (DOA) of the signal, and use them to calculate beamforming vectors which are used to track and locate the antenna beam on the mobile/target. Smart antennas should not be confused with reconfigurable antennas, which have similar capabilities but are single element antennas and not antenna arrays. Smart antenna techniques are used notably in acoustic signal processing, track and scan radar, radio astronomy and radio telescopes, and mostly in cellular systems like W-CDMA, UMTS, and LTE. Smart antennas have many functions: DOA estimation, beamforming, interference nulling, and constant modulus preservation..
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Early commercial LCR bridges used a variety of techniques involving the matching or "nulling" of two signals derived from a single source. The first signal was generated by applying the test signal to the unknown and the second signal was generated by using a combination of known- value R and C standards. The signals were summed through a detector (normally a panel meter with or without some level of amplification). When zero current was noted by changing the value of the standards and looking for a "null" in the panel meter, it could be assumed that the current magnitude through the unknown was equal to that of the standard, and that the phase was exactly the reverse (180 degrees apart).
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Net ecosystem production (NEP) and climate changes are the all encompassing factors that have been shown to have a direct relationship with methane emissions from wetlands. In wetlands with high water tables, NEP has been shown to increase and decrease with methane emissions, most likely due to the fact that both NEP and methane emissions flux with substrate availability and soil composition. In wetlands with lower water tables, the movement of oxygen in and out of the soil can increase the oxidation of methane and the inhibition of methanogenesis, nulling the relationship between methane emission and NEP because methane production becomes dependent upon factors deep within the soil. A changing climate affects many factors within the ecosystem, including water table, temperature, and plant composition within the wetland—all factors that affect methane emissions.
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Zero-forcing (or null-steering) precoding is a method of spatial signal processing by which the multiple antenna transmitter can null multiuser interference signals in wireless communications. Regularized zero-forcing precoding is enhanced processing to consider the impact on a background noise and unknown user interference, where the background noise and the unknown user interference can be emphasized in the result of (known) interference signal nulling. In particular, null-steering is a method of beamforming for narrowband signals where we want to have a simple way of compensating delays of receiving signals from a specific source at different elements of the antenna array. In general to make better use of the antenna arrays, we sum and average the signals coming to different elements, but this is only possible when delays are equal.
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The same technique has now been applied at a number of other astronomical telescope arrays, including the Navy Prototype Optical Interferometer and the IOTA array and soon the VLTI, CHARA array and MRO Interferometers. Projects are now beginning that will use interferometers to search for extrasolar planets, either by astrometric measurements of the reciprocal motion of the star (as used by the Palomar Testbed Interferometer and the VLTI) or through the use of nulling (as will be used by the Keck Interferometer and Darwin). A detailed description of the development of astronomical optical interferometry can be found here. Impressive results were obtained in the 1990s, with the Mark III measuring diameters of hundreds of stars and many accurate stellar positions, COAST and NPOI producing many very high resolution images, and ISI measuring stars in the mid-infrared for the first time.
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The University of Sydney is associated with five Nobel laureates: in chemistry John Cornforth (alumnus; the only Nobel Laureate born in New South Wales) and Robert Robinson (staff); in economics, John Harsanyi (alumnus); and in physiology or medicine, John Eccles and Bernard Katz (both staff). The School of Physics has played an important role in the development of radio astronomy in particular: Ruby Payne-Scott conducted the first interferometric observations in radio astronomy with the sea-cliff interferometer at Dover Heights; alumnus Ron Bracewell proposed the nulling interferometer to image extrasolar planets, made contributions to the theory of the Fourier Transform and X-ray tomography, and proposed the idea of the Bracewell probe in SETI; and alumnus Bernard Mills led the construction of the Mills Cross Telescope and Molonglo Observatory Synthesis Telescope in the ACT. School of Physics alumnus and Crafoord Laureate Edwin Salpeter discovered the form of the initial mass function of stars, the importance of beryllium-8 in stellar nuclear fusion, and independently with Yakov Zel'dovich proposed the black hole accretion disk model of active galactic nuclei. The Apollo 14 Mission Scientist Philip K. Chapman and the first Australian-born astronaut to fly in space Paul Scully-Power are both alumni of the University.
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