102,540 research outputs found
An inviscid model of the solar wind
Inviscid, thermal conductive, spherically symmetric solar wind model - model solution by integration of mass, momentum, and energy conservation equation
Resolving the wave-vector and the refractive index from the coefficient of reflectance
We resolve the existing controversy concerning the selection of the sign of
the normal-to-the-interface component of the wave-vector of an
electromagnetic wave in an active (gain) medium. Our method exploits the fact
that no ambiguity exists in the case of a {\em film} of the active medium since
its coefficient of reflectance is invariant under the inversion of the sign of
. Then we show that the limit of the infinite film thickness determines a
unique and physically consistent choice of the wave-vector and the refractive
index. Practically important implications of the theory are identified and
discussed.Comment: 6 pages, 4 figure
SAR data compression: Application, requirements, and designs
The feasibility of reducing data volume and data rate is evaluated for the Earth Observing System (EOS) Synthetic Aperture Radar (SAR). All elements of data stream from the sensor downlink data stream to electronic delivery of browse data products are explored. The factors influencing design of a data compression system are analyzed, including the signal data characteristics, the image quality requirements, and the throughput requirements. The conclusion is that little or no reduction can be achieved in the raw signal data using traditional data compression techniques (e.g., vector quantization, adaptive discrete cosine transform) due to the induced phase errors in the output image. However, after image formation, a number of techniques are effective for data compression
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