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A technique is proposed for measuring volcanic deformation on the order of centimeters per day to centimeters per year. An airborne multifrequency pulsed radar, tracking passive ground reflectors spaced at 1 kilometer intervals ov...
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A technique is proposed for measuring volcanic deformation on the order of centimeters per day to centimeters per year. An airborne multifrequency pulsed radar, tracking passive ground reflectors spaced at 1 kilometer intervals over a 50 square kilometer area is employed. Identification of targets is accomplished by Doppler and range resolution techniques, with final relative position measurements accomplished by phase comparison of multifrequency signals. Atmospheric path length errors are corrected by an airborne refractometer, meteorological instruments, or other refractive index measuring devices. Anticipated system accuracy is 1-2 cm, with measuring times on the order of minutes. Potential problems exist in the high intrinsic data assimilation rate required of the system to overcome ground backscatter noise.
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Helium-neon, neodymium (YAG), and CO2 laser radar systems are reviewed. Laser properties and hazards are discussed. Modulation techniques; optical detectors; beam steering; and signal processing are considered. System losses; atmo...
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Helium-neon, neodymium (YAG), and CO2 laser radar systems are reviewed. Laser properties and hazards are discussed. Modulation techniques; optical detectors; beam steering; and signal processing are considered. System losses; atmospheric propagation; noise sources; and optical clutter are described. Laser radar range equations are analyzed. Applications including ranging, airborne surveillance and reconnaissance, wind velocity measurement, terrain following, and obstacle avoidance are treated.
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Flights were conducted E-SLAR (side looking airborne radar) for remote sensing experiments with active microwave techniques (X-band). The analog recorded data were mainly evaluated by visual methods to judge the system and its use...
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Flights were conducted E-SLAR (side looking airborne radar) for remote sensing experiments with active microwave techniques (X-band). The analog recorded data were mainly evaluated by visual methods to judge the system and its usefulness to solve Earth scientific questions.
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In support of the Space Based Radar (SBR) surveillance system technologies, a satellite simulation model has been multiple radar satellites, simulates the radar beam in order to study the surveillance coverage capabilities of the ...
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In support of the Space Based Radar (SBR) surveillance system technologies, a satellite simulation model has been multiple radar satellites, simulates the radar beam in order to study the surveillance coverage capabilities of the satellites and finally, simulates the detection of airborne targets. This report summarizes the major mathematical concepts involved in the model and provides an overview of the computer implementation of this model. (Canada)
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Applications of bistatic radar when one or both of the units are airborne, are discussed. Scenarios that merit deeper consideration are covert strike and head-on SAR using a stand-off illuminator, either airborne or space-based; a...
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Applications of bistatic radar when one or both of the units are airborne, are discussed. Scenarios that merit deeper consideration are covert strike and head-on SAR using a stand-off illuminator, either airborne or space-based; area air defense with passive ground-based receivers and stand-off illuminators; an airborne picket line to detect stealth aircraft and missiles; AWACS aircraft providing mutual support in ECM environments; and passive surveillance of hostile air space using illuminators of opportunity and an airborne receiver. Scenarios considered impractical are bistatic air-to-air missile guidance using an aircraft other than the launch aircraft as illuminator; passive interdiction using illuminators of opportunity; and scenarios involving a ground based illuminator and an aircraft as the receiver.
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The simplest methods for aerial remote sensing which are least affected by atmospheric opacities are summarized. Radar is preferred for targets off the flight path, and microwave radiometry for targets along the flight path. Radar...
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The simplest methods for aerial remote sensing which are least affected by atmospheric opacities are summarized. Radar is preferred for targets off the flight path, and microwave radiometry for targets along the flight path. Radar methods are classified by ability to resolve targets. Techniques which do not require target resolution are preferred. Among these techniques, polarization methods appear most promising, specifically those which differentiate the expected relatively greater depolarization by icebergs from that by ships or which detect doubly-reversed circular polarization.
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Polarimetric synthetic aperture radar (SAR) has been used for a variety of dual-use research applications since the 1940s. By measuring the direction of the electric field vector from radar echoes, polarimetry may enhance an analy...
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Polarimetric synthetic aperture radar (SAR) has been used for a variety of dual-use research applications since the 1940s. By measuring the direction of the electric field vector from radar echoes, polarimetry may enhance an analyst's understanding of scattering effects for both earth monitoring and tactical surveillance missions. Polarimetry may provide insight into surface types, materials, or orientations for natural and man-made targets. Polarimetric measurements may also be used to enhance the contrast between scattering surfaces such as man-made objects and their surroundings. This report represents an initial assessment of the utility of, and applications for, polarimetric SAR at Ku-band for airborne or unmanned aerial systems.
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The Defense Science Board Task Force was formed to address questions related to the development of X-band, active electronically steered arrays (AESAs) for airborne platforms. Areas focused on were advanced radar capabilities for ...
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The Defense Science Board Task Force was formed to address questions related to the development of X-band, active electronically steered arrays (AESAs) for airborne platforms. Areas focused on were advanced radar capabilities for ground targets and air targets. The airborne radar inventory can be divided into three broad categories: (1) Air target surveillance and cueing radars mounted in rotodomes (e.g., AWACS, E-2O). (2) Nose-mounted fighter radars for air and ground targets (e.g., F-i 5, F-i 6, F-22, JSF). (3) Side- looking radars for ground reconnaissance, surveillance, and cueing (e.g., U-2, JSTARS, Global Hawk). Categories (2) and (3) are dominated by X-band radars; the insertion of AESA technology into category (3) was the primary subject for this task force.
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The air transportation system of the future will need to support much greater traffic densities than are currently possible, while preserving or improving upon current levels of safety. Concepts are under development to support a ...
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The air transportation system of the future will need to support much greater traffic densities than are currently possible, while preserving or improving upon current levels of safety. Concepts are under development to support a Next Generation Air Transportation System (NextGen) that by some estimates will need to support up to three times current capacity by the year 2025. Weather and other atmospheric phenomena, such as wake vortices and volcanic ash, constitute major constraints on airspace system capacity and can present hazards to aircraft if encountered. To support safe operations in the NextGen environment advanced systems for collection and dissemination of aviation weather and environmental information will be required. The envisioned NextGen Network Enabled Weather (NNEW) infrastructure will be a critical component of the aviation weather support services, providing access to a common weather picture for all system users. By taking advantage of Network Enabled Operations (NEO) capabilities, a virtual 4-D Weather Data Cube with aviation weather information from many sources will be developed. One new source of weather observations may be airborne forward-looking sensors, such as the X-band weather radar. Future sensor systems that are the subject of current research include advanced multi-frequency and polarimetric radar, a variety of Lidar technologies, and infrared imaging spectrometers.
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