Satlink Tool : A tool for analysing GEO Satcom¶

INTRODUCTION¶

SATCOM is the term used for communication via satellite. In this communication a signal is transmitted from the Earth up to a satellite, and then is received back at a different location on Earth. When the satellite is located on a geostationary orbit this process is called GEO satellite communication. The global analysis of a GEO satellite communication system depends on many different parameters: the position of the satellite and earth stations, the characteristics of analog RF links, the satellite payload, the environment and the characteristics of the digital link. The main analysis tool is the link budget.

In a signal transmission, the link budget takes into account all the attenuation due to the environment and the equipment and it give us a result in terms of power, noise temperature, antenna parameters and service of the satellite communication system.

Objective¶

The aim of this project is to develop a comprehensive tool in LabVIEW that will offer future students the ability to test different satellite links and derive the end-to-end system performance. This software will offer the possibility to, from a set of input parameters, creatively show the expected link budget of the satellite in order to determinate parameters like EIRP, G/T or BER. In addition, since a MOOC (Massive Open Online Course) in SATCOM is intended to start in June 2015, it would be an interesting option to distribute this program through the website of the SCS program.

This educational environment is developed to be applied in order to facilitate the comprehension of the design and performance of satellite systems, specially aims at Geostationary satellites. GEO satellites are those that have a circular orbit around the Earth at an altitude about 36000 Km above the Equator's line.Figure 1 shows a GEO satellite in orbit above the equator line. These satellites has been used in several applications, playing an important role in global communications, television broadcasting, weather forecasting and defence and intelligence applications.

 
Figure 1 - Geostationary orbit above the Equator. The orbit period is equal to a sidereal day,
giving the impression that the satellite is stationary in relation at rotation of the Earth.

Contents¶

In this wiki is presented the work we carried out during the third project of the specialized master Space Communication Systems in order to implement the tool previously mentioned and how to use it. Thus, this wiki site is structured as follows:

• Brief reminder of the theory of the link budget and the parameters it involves.
• Description and implementation of the interface.
• Tests and results.
• Tool user manual.
• Further improvements.

Bibliography¶

Maral, Gérald / Bousquet, Michel. Satellite Communication System.-5th ed. UK, 2009.

Authors¶

Ederson RIBAS MACHADO
Anna SERRA FONT

Supervisor¶

Laurent FRANCK, responsible for the Toulouse site of Télécom Bretagne.