The earth-atmosphere stray light can lower contrast ratio and SNR of spatial optical remote sensors, or even fail the system at certain conditions. Errors in the calculation of the stray light illuminance based on point source are very large, for the satellite’s altitude is only several hundred kilometers and far less than the radius of the earth. This paper proposed a stray light illuminance c...

Global Navigation Satellite Systems (GNSSs) such as GPS, GLONASS, and the future Galileo and BeiDou, have demonstrated to be a valid and efficient system for various space applications in Low Earth Orbit (LEO), such as spacecraft orbit and attitude determination, rendezvous and formation flight of two or more spacecrafts, and timing synchronization. A GNSS presents a number of significant advan...

VoIP PERFORMANCE IN NGEO SATELLITE IP NETWORKS WITH ON-BOARD PROCESSING CAPABILITY In this thesis study, an adaptive routing policy utilizing the real-time network information of a two-layered satellite network is introduced. In a satellite network, depending on the requirements and properties of services provided, various kinds of satellites from different orbits can be employed. Geostationary...

Introduction GPS receivers are now widely used for Low Earth Orbit (LEO) spacecraft applications for both scientific and commercial programmes. New applications are also under study, such as navigation in Geostationary Earth Orbit (GEO) and Geostationary Transfer Orbit (GTO), space rendezvous manoeuvres and atmospheric reentry, for which GPS receivers are promising candidates as navigation sens...

Laser-powered lightcraft systems that deliver microsatellites to low earth orbit have been studied for the Air Force Research Laboratory. One result of this Study has been discovery of the significant influence of laser wavelength on the power lost during laser beam propagation through Earth’s atmosphere and in space. Here, energy and power losses in the laser beam are extremely sensitive to wa...

User terminals for Communications-On-The-Move (COTM) systems and Low Earth Orbit (LEO) and Medium Earth Orbit (MEO) satellite ground terminals require antennas with high gain and steerable beams. LEO cubesats offer unprecedented opportunities for scientific discoveries as well as commercial space adventures. Internet is provided to aeroplanes, ships and defence and other vehicles by COTM system...

An orbiting 'photon clock' is proposed to test directly the relativity of simultane-ity of special relativity. This is done by comparison of the arrival times at a ground station of three microwave signals transmitted by two satellites following the same low Earth orbit. A similar experiment, that may be performed using synchronised signals from two GPS satellites with the receiver on a single ...

The purpose of this rersearch is to analyze the effective application of particular earth orbits in dynamical modeling of relative motion problem between two spacecraft. One challenge in implementing these motions is maintaining the relations as it experiences orbital perturbations (zonal harmonics J2 and J3), most notably due to the Earth’s oblateness. Certain aspects of the orbital geometry c...