
The figure depicts two digital waveforms and a block diagram of a digital phase meter for measuring the difference between their phases. This digital phase meter is being developed for incorporation into a laser heterodyne interferometer in a metrological apparatus, but could also be ...
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To support NASA’s planned 20-year mission to provide sustained global precipitation measurement (EOS-9 Global Precipitation Measurement (GPM)), a deployable antenna has been explored with an inflatable thin- membrane structure. This design uses a 5.3×5.3-m inflatable parabolic ...
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A prototype of an advanced robotic vision system both (1) measures its own motion with respect to a stationary background and (2) detects other moving objects and estimates their motions, all by use of visual cues. ...
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A wide-band penetrating radar system for measuring the thickness of sea ice is under development. The need for this or a similar system arises as follows: Spatial and temporal variations in the thickness of sea ice are ...
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Interferometric synthetic aperture radar (InSAR) has been shown to provide very sensitive measurements of surface deformation and displacement on the order of 1 cm. Future systematic measurements of surface deformation ...
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A proposed device for combining or switching electromagnetic beams would have three ports, would not contain any moving parts, and would be switchable among three operating states:
This design allows broadband power combining with high isolation between the H port and E port, and achieves a lower insertion loss than any other broadband planar magic-T. Passive micro wave/...
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The Next Generation Flight Controller Trainer (NGFCT) is a relatively inexpensive system of hardware and software that provides high- fidelity training for space-shuttle flight controllers. NGFCT provides simulations into which are integrated the behaviors of emulated space-shuttle vehicle onboard general-purpose computers (GPCs), mission-control center (MCC) displays, and space-shuttle systems as ...
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A quasi-optical transmission line (QOTL) has been developed as a low-loss transmission line for a spaceborne cloud-observing radar instrument that operates at a nominal frequency of 94 GHz. This QOTL could also readily be redesigned for use in terrestrial ...
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Single-event upsets (SEUs) pose great threats to avionic systems’ state machine control logic, which are frequently used to control sequence of events and to qualify protocols. The risks of SEUs manifest in two ways: (a) ...
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A report discusses integrating multiple memory modules on the high-speed serial interconnect (IEEE 1393) that is used by a spacecraft’s inter-module communications in order to ease data congestion and provide for a scalable, strong, flexible system that can meet new system-level mass memory requirements.
A document discusses placing memory modules on the high-speed
serial interconnect, which is used by a spacecraft’s computer
elements for inter-processor communications, to allow all multiple
computer system architectures to access the spacecraft data
storage at the same time. Each memory board is identical electrically
and receives its bus ...
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A document discusses a method by which GMSK (Gaussian
minimum shift keying) modulation and a pseudonoise (PN)
ranging signal may be combined. By isolating the in-phase and
quadrature components after carrier lock, and extracting their
low-pass and band-pass filtered components, there is enough
information available to both demodulate data and ...
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