Advanced Signal Processing Techniques in Local User Terminals for Search & Rescue Systems Based on MEO Satellites

Code:    ESTEC 17713/03/NL/LvH/jd
Funder:    Private Company
Company:    European Space Agency
Start date:    2003 December 17th
End date:    2004 December 13th
Keywords:    Seach And Rescue, SAR, TDOA, FDOA, arrays
Web site:    http://www.cospas-sarsat.org

SPCOM Participants:    Pau Closas Gómez, Juan Fernández Rubio and Carles Fernandez Prades
SPCOM Responsible:    Carles Fernandez Prades

Summary

The purpose of a Search and Rescue (SAR) satellite-based system is to provide distress alert and location data for distress radiobeacons for subsequent distribution to SAR authorities. This system is based upon a set of signal replicas relied by a satellite constellation, parameter estimation, Time and Frequency Difference of Arrival, of such replicas allows an estimation of the beacon position and thus a rescue team can proceed. Nowadays, this service is been offered by the Cospas-Sarsat international programme, which is based on two satellite constellations: 4 LEO satellites and 3 GEO satellites. With the advent of Galileo, the capabilities of the SAR system are to be improved by using its nearly of 30 satellites in Medium Earth Orbit, the activity entitled 'Advanced Signal Processing Techniques in Local User Terminals for Search and Rescue Systems Based on MEO Satellites' is a complete work of the topic containing: a description of the system, an analytical review of the existing and new distress signal structure, a number of parameter estimation techniques, comparisons between exiting and proposed distress beacon and a rigorous study on the use of antenna array techniques applied to the SAR system. Finally a Matlab-based software has been developed in order to simulate all methods and scenarios exposed in the work.

Conference publications

[1] C. Fernandez Prades, P. Closas Gómez and J. Fernández Rubio, "Advanced Signal Processing Techniques in Local User Terminals for Search and Rescue Systems Based on MEO Satellites", Institute of Navigation Satellite Division Technical Meeting, September 2005.

[2] P. Closas Gómez, C. Fernandez Prades, J. Fernández Rubio, G. Seco and I. Stojkovic, "Design of Local User Terminals for Search and Rescue Systems with MEO satellites", ESA Workshop on Satellite Navigation User Equipment Technologies, December 2004.