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Objectives
The project involves the analysis, design, implementation and validation of a fully passive and highly accurate ranging system for geostationary satellites. SES performs the requirements definition, system and software engineering. Fraunhofer Insitute of Technology is in charge of the development of the signal processing equipment.
The goals are to develop a system that:
- Provides highly accurate orbit predictions of geostationary satellites that allow dense collocation (up to 8 satellites) in one orbital box.
- Minimizes the impact of ranging operations on the satellite by avoiding the use of transponder invasive techniques. The system shall be payload signal independent.
- Responds to a global demand of geostationary satellite’s tracking and orbit data.
- Minimizes the cost of ranging operations by automating measurements.
The developed technology will allow SES to approach strategic partners, regulatory organizations and space agencies and offer them high quality orbit data on proprietary and/or third party satellites, or sell a turn-key PaCoRa system to operators. Deliverable: A first system deployed over Europe composed of 5 receiving antennas.
Challenges
The system requirements aim to have a system able to measure passively on any kind of modulation scheme, and on bandwidths lower than 10MHz and/or Signal-to-noise ratio lower than 0.
The satellite movement will induce Doppler effect and time variations on the ground. The most complicated scenario occurs on highly inclined geostationary orbits. It will be addressed, and the necessary mechanisms and algorithms will have to be implemented in order to cope with these effects.
In order to produce orbit predictions that allow the collocation of up to 8 satellites in a single orbital slot, the project has to meet challenging requirements on the tracking system. The precision of the tracking data needs to be better than 30ns. Correlation precision and time synchronization between sites will be crucial for the performance of the system.
In order to have a fully passive system, an orbit determination model will be developed in order to compute orbits without a prior knowledge of the satellite maneuvers.
Plan
The Project execution started in June 2010, the deployment of the stations over the European continent took place during the fall of 2012. The Final Review took place in January 2013.
Current Status
The Final Review was successful and the system was accepted. Since then, the system is being further consolidated by comparing its long-term performance to SES’ operational systems. In parallel, efforts are being put in commercialization and publicizing of the product.
