The Global Navigation Satellite System (GNSS) plays an important role in positioning and navigation applications. The Global Positioning Service (GPS) augmentation is to achieve more reliable and accurate navigation solutions. The presently available traditional GNSS receivers are hardware based receivers which are not flexible and cannot be easily upgraded to acquire the signals from other GNS...

This paper investigates satellite-MIMO, space-time coded for diversity gain. Whereas a dual satellite to single antenna terminal link provides shadowing and some multipath diversity gain, a dual antenna terminal provides additional multipath diversity gain. This gain is demonstrated by simulating high resolution time series channel data for urban and highway environments, for SISO, MISO and MIM...

In regions where global navigation satellite systems (GNSS) signals are unavailable, such as underground areas and tunnels, GNSS simulators can be deployed for transmitting simulated signals. Then, a receiver in the simulator coverage outputs position based on received (e.g., Global Positioning System (GPS) L1 this study) transmitted by corresponding simulator. This approach provides periodic u...

This paper presents SPICE testbed, a state-of-the-art Delay Tolerant Networking testbed for satellite and space communications deployed at the Space Internetworking Center, Greece. The core of the testbed relies on the Bundle Protocol and its architecture has been designed to support multiple DTN implementations and a variety of underlying and overlying protocols. SPICE testbed is equipped with...

This paper focuses on the Teledesic satellite constellation, which is an attempt to provide high speed, multimedia networking connectivity to any location on the globe. Since the routers (satellites) are in constant motion, this venture is unique and leads to a one-of-a-kind data routing scheme. This concept is still in the design phase, with implementation still a few years away. However, seve...

In this paper, the contact motion between rigid body systems floating in space is formulated and dynamic conditions are investigated in order to capture a non-cooperative satellite. As for the theoretical investigation, impedance matching is discussed for the case in which the robot hand under impedance control approaches and collides with a passive target, and a specific impedance value is def...

This paper describes a project which experimentally validates a generic contact-dynamics toolkit in a Simulink based satellite docking simulator. The simulation software was developed by MDA for supporting the design and verification of the ISS robotic systems and several satellite on-orbit servicing systems. The hardware experiment was performed using an air-bearing supported docking testbed s...

by SHAUN MICHAEL ENDRES This thesis presents methods of simulating and emulating satellite networks, in which the nodes can be orbiting around or located on different planets scattered throughout the solar system. The simulation method works by translating a satellite scenario described in a common orbit propagator to a form that can be interpreted by a popular network simulator. This merger re...

After the successful European gravity mission GOCE (Gravity field and steady-state Ocean Circulation Explorer), which provided an unprecedented high resolution static global map of the Earth's gravity field, the European Space Agency has proposed several preparatory studies for a Next Generation Gravity Mission. The NGGM mission objective aims at measuring the temporal variations of the Earth g...

Congestion in the Internet results in wasted bandwidth and also stands in the way of guaranteeing QoS. The effect of congestion is multiplied many fold in Satellite networks, where the resources are very expensive. Thus congestion control has a special significance in the performance of Satellite networks. In today’s Internet, congestion control is implemented mostly using some form of the de f...