Frequency Sounding
Mostrando 1-4 de 4 artigos, teses e dissertações.
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1. Characterization of traveling ionospheric disturbances over low latitude brazilian region associated to Perkins plasma instability generated at medium latitudes / Caracterização de distúrbios ionosféricos propagantes na região de baixas latitudes no setor brasileiro associados à instabilidade de plasma Perkins gerada em médias latitudes
With ground based measurements of OI 630 nm emission, by using all-sky imaging system installed at Cachoeira Paulista, we investigated the occurrence of specific events of Medium Scale Traveling Ionospheric Disturbances (MSTIDs), which occurred during nights geomagnetically quiet. Probably, these disturbances are associated with Perkins plasma instability ge
Publicado em: 2010
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2. MEASUREMENT AND ANALYZE OF UWB INDOOR CHANNEL TEMPORAL DISPERSION IN SEVERAL ENVIRONMENT TYPES / MEDIDAS E ANÁLISE DA DISPERSÃO TEMPORAL DO CANAL DE PROPAGAÇÃO UWB INDOOR EM VÁRIOS TIPOS DE AMBIENTES
This work presents an analysis of the ultra wideband (UWB) channel temporal dispersion characteristics evaluated from the frequency sounding technique over a bandwidth of 850MHz at seven different indoor environment. In each environment, the channel temporal dispersions parameters were assessed in terms of mean delay, delay spread and coherence bandwidth. An
Publicado em: 2005
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3. CARACTERIZAÇÃO ESPAÇO-TEMPORAL DO CANAL RÁDIO MÓVEL / SPACE-TIME CHARACTERIZATION OF THE MOBILE RADIO CHANNEL
This work presents the results of an investigation of the use of the Frequency Sounding technique in Mobile Radio Channel`s Space-Time Dispersion characterization. Hence, some changes in the classical Frequency Sounding Technique were employed: a set of antennas was built and calibrated and an algorithm for signal pos processing was tested. A measurement cam
Publicado em: 2003
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4. Estudo das variacoes das funcoes-peso em microondas sobre o Brasil, utilizando o modelo ATM / Study of variations of the weighting functions over Brazil, using the ATM model
The weighting functions of the ten Advanced Microwave Sounding Unit (AMSU) channels of Advanced TIROS-N/NOAA Operational Vertical Sounder (ATOVS), calculated from the Atmosphere Transmission at Millimetric and Submillimetric Wavelengths (ATM) model, were compared with those from the AMSU/ATOVS. Among the ten channels, five refer to the oxygen absorption line
Publicado em: 1999