Air Force Research Laboratory's Distributed Architecture and Simulation Laboratory (DASL) is designed to support the development of new concepts in space systems. One new concept is AFRL’s TechSat 21 program. TechSat 21 is a cluster of formation-flying and cooperating satellites. TechSat 21 poses significant challenges to satellite operations. The ground control station must be capable of monit...

pertinent to the prospective atmospheric propagation effects Satellite Propagation in the 20to 30GHz Frequency Range, IEEE Trans. Ant. Prop. Ippo1ito, L. J., R. D. Kau1 , and R. G. Na11ace, Propagation Handbook for Sate11ite. Systems Design, A Summary of Propagation Impairments on 10 to 100 GHz Sate11ite. DESCANSO NASA Propagation Program. Propagation Effects Handbook for Satellite Systems Desi...

In order to enhance the availability and the offered Quality of Service (QoS), Land Mobile Satellite Systems (LMSS) will have the option to use simultaneous transmission via two or more satellite as diversity. In this paper the performance of a TDMA and CDMA single user return link employing such a diversity reception is investigated by means of computer simulation using a multi state mobile sa...

In this paper, we propose a unified and interactive mobile learning (M-Learning) model to help with expanding and spreading education in the Arab Homeland countries. The model utilizes a new competitive spot beam satellite communication technology, which enables efficient channel allocation, where communication channels can be allocated to specific and precise areas. The proposed model is refer...

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...

Using satellite cloud images to simulate clouds is one of the new visual simulation technologies in Virtual Reality (VR). Taking the original data of satellite cloud images as the source, this paper depicts specifically the technology of 3D satellite cloud imaging through the transforming of coordinates and projection, creating a DEM (Digital Elevation Model) of cloud imaging and 3D simulation....

This paper presents a number of experimental findings regarding the efficiency of terrestrial protocols when they are used over a satellite link at data rates of about 1.5 Mbits/sec. In particular, we present measurements on TCP/IP and a theoretical model which explains the observed performance and points towards possible ways in which this protocol stack can be used more efficiently on a satel...

Routing in Low-earth-orbit (LEO) satellite system involves the choice of inter-satellite links (ISLs) that connects two home satellites of the mobile terminals. We use a mesh model to formulate the LEO system and proposed 4 mesh-based algorithms. The objective is to minimize the new call blocking probability and the forced termination probability. Also, due to the dynamic topology of the LEO sy...

The tradeoff between picture quality and bandwidth usage is one of the most prominent issues in the world of broadcasting. Since broadcasters are able to simultaneously transmit multiple streams in a channel, they face the challenge of guaranteeing a certain picture quality required by each of the video streams transmitted while maximizing the number of video streams carried in each channel. To...

* Corresponding author. **This research is supported by the Russian Foundation of Basic Research (grants 03-01-00812, 04-07-90350) and Presidium of Far-East Branch Russian Academy of Sciences. Abstract This paper is devoted to description of some experience in reception and processing satellite information of the Chinese meteorological satellites FengYun. Geostationary satellite FY-2B is an ana...