Accurate and stable frequency reference sources are critical for commercial, navigation, military, and scientific space applications. Each piece of flight hardware has requirement-types that are generic such as size, weight, power, and reliability, and requirement-types that are specific to the hardware function. The key requirement-types for frequency reference sources are phase noise and stab...

A Satellite Attitude Dynamics Simulator (SADS) has been developed to facilitate the research and development of spacecraft flight attitude control software at the Naval Postgraduate School in Monterey, CA. The simulator provides a real-time 3 degree of freedom (3DOF) synthetic spacecraft hardware-in-the-loop environment, that includes realistic angular motions, sensor-effector delays, and contr...

Satellite services (e.g. Internet-over-Satellite or GPS) are getting more and more important in our lives, whereby the operational area is still growing. To guarantee those services, reliable simulation tools are necessary to scale and validate actual and future satellite systems. Therefore, this paper gives an overview about development, functionalities and benefit of a satellite simulation fr...

We outline how an agent’s shared autonomy considerations affect its interaction in a team. A unified model of acting and speaking will be presented that includes teaming and autonomy. This model is applied to the domain of satellite constellation. We introduce our simulator and outline our application of autonomy and teaming concepts.

In this paper the basic principles for the design and implementation of a wide-band statistical model for the LMS (land mobile satellite) channel at various frequency bands are presented. The model is valid for different services including communications, broadcast, navigation, etc. The simulator implementing the model is suitable of the study of new systems, including those using LEO and other...

This paper evaluates the effects of bandwidth asymmetry introduced in a geostationary DVB-RCS satellite architecture on the Round Trip Time of the Transmission Control Protocol (TCP). In particular, it shows the analytical analysis of the round trip time (RTT) of a TCP connection and defines a bandwidth asymmetry index, which is the key point of the work. The final goal is the provision of anal...

The importance of space robots in satellite servicing, in EVA assistance, in removing orbital debris and in space exploration is growing driven by space commercialization and exploration efforts. A successful deployment of such robots requires analytical and experimental task validation. With this aim, we present the main characteristics of the software and hardware space robot simulator develo...

A method for deriving attenuation time-series on fixed satellite or terrestrial links is described. The method uses meteorological forecast and radar data and permits time coincident derivations for multiple sites that include the inherent spatial correlation properties. The paper describes the approach adopted in the technique and presents preliminary results for two sites in the UK. The time-...

In this paper a multi-state model is developed for land mobile satellite systems, based upon measurements in an urban environment at 1.8 GHz, using Nakagami distribution. Multi-state models can yield more accurate fading amplitude time series than can single state models. Here pdfs have been derived using the second order statistics of LCR and AFD data. This simulator is general, and can be con...

We analyze the load of the inter-satellite links in polar satellite constellations. Starting from simple considerations on the structure of the underlying network topology, we derive the probability of use of diierent families of links, with various hypotheses on the nature of the traac. Our analysis leads to a simple, practical evaluation of the asymptotical link load, which depends on the pos...