Cassegrain antenna feed system, model ASF-108 FINAL engineering report
Design and performance characteristics of Cassegrain antenna feed system
FEED SYSTEM↗
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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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On the use of an array of circumferential slots on a large cylinder as an omnidirectional antenna.
Array of circumferential slots on large cylinder as omnidirectional antenna
OMNIDIRECTIONAL ANTENNA↗
Synthesis of improved feeds for large circular paraboloids.
Improved feed synthesis using multimodes for large circular paraboloids at Parkes
PARABOLIC REFLECTOR↗
Coupled waveguide antennas.
Coupled waveguides structure proposed as leaky- wave antenna, extending previous coupled-mode theory
COUPLED MODE↗
A 3 Gc/s scale model of a submerged VLF ANTENNA using lossy ceramic powder.
Scale model of submerged VLF antenna using lossy ceramic powder to model ice and snow for submarine communication, geophysics, etc
DIELECTRIC CONSTANT↗
Dynamic stability of a gravity gradient stabilized satellite having long flexible antennas.
Radio astronomy satellite with extendible antennas achieves gravity gradient stabilization while receiving electromagnetic radiation, analyzing dynamic behavior and effect of passive damper
ANTENNA FIELD↗
Irreversible power and radiation resistance of antennas in magnetoionic media.
Radiation resistance of antennas in magnetoplasma, considering inapplicability of reversible power concept to steady state mode
POWER TRANSMISSION↗
Idealized Antenna Patterns for Use in Communication-satellite Interference Studies
Idealized antenna patterns for communication satellite interference studies
COMMUNICATIONS SATELLITE↗
Aeronomy field station
Aeronomy field station antenna systems to operate with instruments for measuring ionospheric drifts, vertical incidence absorption, and partial reflections
RADIO REFLECTION↗
Rotating interferometer and its use in measuring the spread and coherence ratio of a scattered radio wave.
Rotating interferometer measuring spread and coherence ratio of scattered radio wave
ATMOSPHERIC SCATTERING↗
Large ground antenna performance with solar noise jamming.
Large ground antenna performance with solar noise jamming
ANTENNA FIELD↗
The traveling-wave V-antenna and related antennas.
Traveling wave V antenna, discussing parameter variation effect on radiation patterns
RADIATION DISTRIBUTION↗
Measuring large-antenna radiation.
Large antenna radiation from radio astronomy Explorer satellite determined on basis of antenna current distribution
SATELLITE INSTRUMENTATION↗
Behavior of Gemini spacecraft antennas in an ionized medium.
Gemini spacecraft antennas performance during reentry into ionized medium, discussing electron concentration profiles, nonearth atmosphere extrapolation and antenna breakdown effect
ATMOSPHERIC ENTRY↗
Radiation from a recessed slot in a coated cylinder.
Radiation pattern lobing structure elimination for recessed annular slot in coated metal cylinder
SLOT ANTENNA↗
Radiometric observations and the cloud-melting zone.
Cloud melting zone, noting increased antenna temperature for radiation trapping between cloud layer and ground
ANTENNA FIELD↗
Far-field radiation patterns of aperture antennas by the Winograd Fourier transform algorithm
A more time-efficient algorithm for computing the discrete Fourier transform, the Winograd Fourier transform (WFT), is described. The WFT algorithm is compared with other transform algorithms. Results indicate that the WFT algorithm in antenna analysis appears to be a very successful application. Significant savings in cpu time will improve the computer turn around time and circumvent the need to resort to weekend runs.
Heisler, R.↗
Doppler radar echoes of lightning and precipitation at vertical incidence
Digital time series data at 16 heights within two storms were collected at vertical incidence with a 10-cm Doppler radar. On several occasions during data collection, lightning echoes were observed as increased reflectivity on an oscilloscope display. Simultaneously, lightning signals from nearby electric field change antennas were recorded on an analog recorder together with the radar echoes. Reflectivity, mean velocity, and Doppler spectra were examined by means of time series analysis for times during and after lightning discharges. Spectra from locations where lightning occurred show peaks, due to the motion of the lightning channel at the air speed. These peaks are considerably narrower than the ones due to precipitation. Besides indicating the vertical air velocity that can then be used to estimate hydrometeor-size distribution, the lightning spectra provide a convenient means to estimate the radar cross section of the channel. Subsequent to one discharge, we deduce that a rapid change in the orientation of hydrometeors occurred within the resolution volume.
Zrnic, D. S.↗