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How Scilab and the CelestLab toolbox are used for the testing of our satellite system

Benoît Helin, Cospas-Sarsat

The Cospas-Sarsat Programme provides, through international cooperation, timely and accurate satellite-based distress alerts to Search and Rescue (SAR) authorities. Cospas-Sarsat is currently undertaking a Demonstration (D&E) and Evaluation Phase for its new Medium-altitude Earth Orbit Search and Rescue system (MEOSAR). This testing phase involves navigation satellites from three constellations (Galileo for Europe, Glonass for Russia and GPS for the USA) with receiving ground stations from ten participating countries.

Simulation tools are required to plan and coordinate the tests among the participants’ ground station locations (e.g., tools to calculate satellite passes, beacon-satellite-ground station co-visibility periods and geometry configurations) and to process the data collected by participants following the same agreed methods (e.g., statistical and geometrical analyses).

The review of available commercial off-the shelf software concluded that Scilab, complemented by the CelestLab toolbox, has major assets to conduct the above tasks, allowing high level programming of required features. An additional advantage is that this software is freely available to all participants, who might not have the proper tools or the required expertise in space mechanics to develop their own.

This presentation will show the benefits of using Scilab with the CelestLab toolbox for the Cospas-Sarsat MEOSAR D&E testing and the areas in which it has been used, including:

test planning (e.g., definition of time periods for testing),
validation of processing methods developed by participants,
cross-verification of algorithms proposed by participants regarding the MEOSAR system, and
sharing of processing scripts.

In addition, the CelestLab toolbox in conjunction with the Image Processing Design toolbox allows processing of images of the frequency band recorded during the tests with the addition of information derived from space mechanics calculation.