We address the problem of interference as related to Satellite Personal Communication Networks (S-PCNs). Basic low Earth orbit (LEO) constellation is considered. The paper uses combined adaptive antenna arrays and adaptive filtering technique. This hybrid linear adaptive technique provides improved performance eliminating interference, particularly uncorrelated signals residing in the antenna s...

Global Navigation Satellite Systems (GNSSs) were originally introduced to provide positioning and timing services for terrestrial Earth users. However, space users increasingly rely on GNSS for spacecraft navigation and other science applications at several different altitudes from the Earth surface, in Low Earth Orbit (LEO), Medium Earth Orbit (MEO), Geostationary Earth Orbit (GEO), and feasib...

Cloud cover is an important factor limiting the earth observation efficiency of optical imaging satellites. Existing solutions include avoiding cloudy time windows by onboard cloud detectors and ground monitors, which are difficult to improve satellite in time. In order solve problem, firstly, a Geostationary Earth Orbit (GEO) Low (LEO) satellites cooperation scheme using information provided G...

Recent technological advances have accelerated a renaissance in usage of non-geostationary (non-GSO) communication satellites in provision of various services domestically and globally. Early ventures into communication satellites have used satellites in low Earth orbits. The main reasons for this mode of operation were that the booster technology was not available to lift satellites into a hig...

The space environment is a complex, orbit dependent phenomenon. Regardless of orbit, the external surfaces of a spacecraft will be exposed to photons, charged particles and solid particles such as micrometeoroids. Vehicles in low earth orbit (LEO) must be designed to withstand additional environmental hazards such as hyper-velocity impacts by man-made orbital debris and erosion of external surf...

Abstract Positioning, Navigation and Timing (PNT) are services generally provided by Global Satellite Systems (GNSS). GNSS reside in medium to high orbital altitudes from the Earth’s surface, resulting weak signal reception. However, user applications increasingly need of higher power strength or alternative PNT solutions. An influx satellites Low Earth Orbit (LEO) driving such innovation techn...

in this paper, new features of satellite configuration, such as ip network  based infrastructure and separated signaling and media  are considered to propose a variety of satellite configurations in different orbits. because of their  different altitude in space such as low earth orbit(leo) and geostationary orbit (geo). a test bed used to test call setup delay in a one space link to process th...

satellite orbit determination is a method of determining the state vector, i.e., position and velocity, of a low earth orbiting (leo) satellite or interplanetary spacecraft. during the past two decades, many satellites with various applications including geodetic applications have been launched at low altitudes. for instance, topex / poseidon, champ, grace and goce are the examples of the geode...

Abstract A model for the Low Earth Orbit (LEO) satellite communications channel is proposed in this paper. This model is validated through real measurements gathered from a satellite in LEO for a wide range of elevation angles. It is shown that that the burst statistics of the channel are sufficiently described by a multiplestate Fritchman model and four-state Markov model. This model has been ...

Charge–discharge behavior of SONY 18650 lithium-ion batteries for aerospace applications was simulated under low-earth-orbit (LEO) condiions, by using a first-principles based mathematical model. The model determines the capacity fade on the basis of the irreversible loss of active ithium ions due to electrolyte reduction. The capacity fade during LEO cycling was studied for 5 years of continuo...