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Video streaming through Internet faces different challenges caused by network performance and heterogeneity nature of internet. The larger the distance between end-user and streaming server the stream passes through different networks and causes delays which affect the user quality of experience (QoE). An optimal approach to minimize delays and offer high video quality is Cache implementation. Operators...
Low Earth Orbit (LEO) satellites are used for public networking and for scientific purposes. Communication via satellite begins when the satellite is positioned in its orbital position. Ground stations can communicate with LEO satellites only when the satellite is in their visibility region, since LEO satellites move too fast relative to a fixed point (ground station) on the Earth. The major loss...
Method of moments in time domain (MoM-TD) is a comparatively recent yet very interesting numerical technique especially in the case of ultra wide band signals or transients. In this context, the method of moments in time domain (MoM-TD) is very interesting. Implementing the MoM-TD requires three different approaches using Wire Grid Model, Surface Patch Model and the Attachment Model. All MoM-TD implementations...
In this paper three different acquisition algorithms are implemented in a GPS software receiver and compared by the correlation strategy employed. Their theoretical models are first analyzed and then implemented in Mat lab. Both simulated GPS data and realistic signals from a Sat-Surf receiver are used to verify the performance of the acquisition schemes. The software acquisition approach provides...
Ground stations are part of any satellite network, providing communication with satellites. Low Earth Orbit (LEO) satellites are used for public communication and for scientific purposes. The communication quality depends on the performance of the satellite ground station, in addition to that of the satellite. Usually, LEO satellites communicate with ground stations at S-band. Ground stations can...
Ground stations are part of any satellite network, providing communication with satellites. Low Earth Orbit (LEO) satellites are used for public communication and for scientific purposes. The communication quality depends on the performance of the satellite ground station, in addition to that of the satellite. Usually, LEO satellites communicate with ground stations at S-band. Ground stations can...
The scope of this paper is the implementation of a positioning algorithm using the approach of post-processing the measurements taken from a real GPS receiver, in order to assess user's position and performance of the algorithm. Recently, there is an increase interest in positioning techniques based on Global Navigation Satellite Systems so we focus on the performance evaluation of a positioning algorithm...
The 3G mobile services are usually accomplished by implementation of multiband antennas at 900 MHz, 1800MHz and 2100MHz. Multiband antennas enable simultaneous services at these three frequency bands, and consequently the higher emitted power density. Within the vicinity of these antennas it is of interest the non ionizing radiation level to be measured for each frequency, then for three frequencies...
LEO (Low Earth Orbit) environmental satellites provide continuous coverage of Earth, supplying high-resolution meteorological and oceanic observation data. These satellites accomplish their missions based on photo imagery. For photo imagery, it is important the observed area from the satellite to be treated under the same lighting conditions. This can be achieved by keeping a constant Sun position...
Ground stations are part of any satellite network, providing communication with satellites. The communication quality depends on the performance of the satellite ground station, in addition to that of the satellite. Low Earth Orbit (LEO) satellites are used for public communication and for scientific purposes, also. Usually, LEO satellites communicate with ground stations at S-band. The front end...
NOAA (National Oceanic and Atmospheric Administration) - LEO environmental satellites provide continuous coverage of Earth, supplying high-resolution global meteorological, oceanic and space observation data. In addition, these satellites are part of the international COSPAS - SARSAT program, which aides search and rescue teams worldwide. The USA segment is referred to as SARSAT (Search and Rescue...
NOAA (National Oceanic and Atmospheric Administration) - LEO environmental satellites provide continuous coverage of Earth, supplying high-resolution global meteorological, oceanic and space observation data. In addition, these satellites are part of the international COSPAS - SARSAT program, which aides search and rescue teams worldwide. The USA segment is referred to as SARSAT (Search and Rescue...
Noise introduces a fundamental limit on the performance of any communication system. Satellite communication systems are particularly susceptible to noise because of their inherent low received power. During the link budget calculations, noises of the equipment and line loss have to be considered. An alternative, but equivalent way of expressing the noisiness of the equipment and line loss is through...
The project "MOST" (micro variability and oscillations of stars) is a Canadian micro satellite space telescope mission. The micro satellite carries a Rumak-Maksutov telescope with an aperture of 15 cm. The size of the satellite is 65 cmtimes65 cmtimes30 cm and the mass is about 65 kg. The goals of the mission are to analyze the inner structure of stars, set a lower limit to the age of the...
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