We report the discovery of a new Milky Way satellite in the constellation Leo, identified in data from the Sloan Digital Sky Survey. It lies at a distance of ∼ 180 kpc, and is separated by . 3 from another recent discovery, Leo IV. We present follow-up imaging from the Isaac Newton Telescope and spectroscopy from the Hectochelle fiber spectrograph at the Multiple Mirror Telescope. Leo V’s helio...

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...

Several analytical and numerical methods exist to solve the orbit propagation of the two-body problem. Analytic solutions are mainly implemented for the unperturbed/classical two-body problem. Numerical methods can handle both the unperturbed and the perturbed two-body problem. The literature is rich with numerical methods addressing orbit propagation problems such as, Gauss-Jackson, Higher ord...

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...

A number of satellite communication systems have been proposed using geosynchronous (GEO) satellites, medium earth orbit (MEO) and low earth orbit (LEO) constellations operating in the Ka-band and above. The next generation broadband satellite systems will use fast packet switching with onboard processing to provide full two-way services to and from earth stations. New services gaining momentum...

This paper investigates a low-Earth orbit (LEO) satellite downlink for high-speed data communication in interference situations. A choke ring horn type antenna is used as the transmitting with an isoflux pattern LEO satellite, which has beam coverage of ±51.6° and bore-sight gain 4.4 dBi at 8 GHz. The receiving on ground station parabolic diameter 11.3 m, it half-power width (HPBW) 0.2° maximum...

Precise (sub-meter level) real-time navigation using a space-capable single-frequency global positioning system (GPS) receiver and ultra-rapid (real-time) ephemerides from the international global navigation satellite systems service is proposed for low-Earth-orbiting (LEO) satellites. The C/A code and L1 carrier phase measurements are combined and single-differenced to eliminate first-order io...

This paper will present the methods adapted to model low earth orbiting (LEO) spacecraft support and an actual implementation of this approach. The results of a comparison of actual human schedulers' performance and the support schedules developed by using the proposed modeling approach will be presented. Indications based on two years of performance tracking of the new approach are that modeli...

Mobility management is an important aspect in LEO (low earth orbit) systems. In terrestrial wireless networks, the movement of the user triggers location updating and determines the paging scheme, while in LEO satellite systems, the location updating and paging is mainly based on the movement of satellite. Terrestrial location management techniques must be altered to fit the LEO systems. This p...

Various methods for kinematic and reduced-dynamic precise orbit determination (POD) of Low Earth Orbiters (LEO) were developed based on zeroand double-differencing of GPS carrier-phase measurements with and without ambiguity resolution. In this paper we present the following approaches in LEO precise orbit determination: – zero-difference kinematic POD, – zero-difference dynamic POD, – double-d...