OLFAR, Orbiting Low Frequency Antennas for Radio Astronomy, will be a space mission to observe the universe frequencies below 30 MHz, as it was never done before with an orbiting telescope. Because of the ionospheric scintillations below 30 MHz and the opaqueness of the ionosphere below 15 MHz, a space mission is the only opportunity for this as yet unexplored frequency range in radio astronomy...

Cloud property data sets derived from passive sensors onboard the polar orbiting satellites (such as the NOAA’s Advanced Very High Resolution Radiometer) have global coverage and now span a climatological time period. Synoptic surface observations (SYNOP) are often used to characterize the accuracy of satellite-based cloud cover. Infrequent overpasses of polar orbiting satellites combined with ...

With the advent of LEO constellations, the operation of multiple ground stations becomes an important factor in maintaining several satellites. With a single ground station, the need to perform anomaly resolution on a low-orbiting satellite becomes difficult with short view times and long durations between revisit. The staffing of several ground stations or specialized remote-operation equipmen...

The space-based component of the Global Observing System and its in situ counterpart form World Weather Watch’s System. (GOS) was established during formation Meteorological Organization (WMO) Watch (WWW). During nearly four decades since WWW, space based GOS evolved from a constellation one or more polar-orbiting meteorological satellites to two constellations comprised at least near-polar-orb...

We investigated utilization of Japanese geostationary meteorological satellite, Multi-functional Transport Satellite (MTSAT) data which is able to provide hourly image to a terrestrial monitoring. Firstly, SZA angular effect in reflectance channel was corrected, then algorithms for daily composite were compared. Hourly measurement of MTSAT increased the chance of observing cloud-free land surfa...

The Federal Aviation Administration has embarked on an historic task of modernizing and significantly improving the national air transportation system. One system that uses the Global Positioning System (GPS) to determine aircraft navigational information is called the Wide Area Augmentation System (WAAS). This paper describes a reliability assessment of one candidate system architecture for th...

Scanning radiometers on earth-orbiting satellites are used to measure the chlorophyll content of the oceans via analysis of the water-leaving radiances. These radiances are very sensitive to the atmospheric correction process, which in turn is polarization dependent. The image created by a scanning radiometer is usually composed of successive scans by two mirror sides and one or several detecto...

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. The duration of the visibility and the communication vary for each LEO satellite pass over the station, ...

Introduction: The satellites of Saturn less than 150 km radius occupy several dynamical niches: within rings (Pan, Daphnis, Atlas, Prometheus, Pandora), Coorbiting (Janus and Epimetheus), orbiting among faint rings or in ring arcs (Aegaeon, Methone, Anthe, Pallene) [1], and populating libration regions of larger moons (Telesto, Calypso, Polydeuces, and Helene). Hyperion orbits between Titan and...

Synchronous satellites of Venus have long been thought unstable, but we use Poincare's surface section technique to show that synchronous quasi-satellites orbiting just outside Venus' Hill sphere are quite stable, at least for centuries. Such synchrosats always remain within a few degrees equator, and drift very slowly in longitude. These could be useful continuous monitoring points on surface,...