Internship in Satellite System Ground Segments Division

Internship title: Scanning Techniques for EUMETSAT GEO network antennas to estimate spacecraft position

The need to accurately point the ground stations’ antennas and to effectively track spacecraft’s trajectories is fundamental to maximise the performance of the radiofrequency links.

The spacecraft trajectory (its position versus time) is typically known with high accuracy, and this trajectory is programmed into the antenna. However, due to environmental disturbances, such as temperature gradient, gravity forces, and manufacturing imperfections, the antenna does not point precisely towards the spacecraft. A technique commonly used for the determination of the true spacecraft position is the conical scanning (conscan) method. During conscan, circular movements are added to the antenna commanded trajectory. These circular movements cause sinusoidal variations in the power of the signal received from the spacecraft by the antenna, and these variations are used to estimate the true spacecraft position.

The purpose of this internship is to study and analyse through simulations and ad-hoc software tools the potential performance of antenna conical scan methods when pointing the antenna to a virtual position in the plane of sky between two GEO spacecraft.

The new S/W simulation tools (mainly MatLab and/or C++) shall be developed or tailored to allow parameterisation of the different scenarios, including degraded cases. This internship will provide students with the possibility to put in practice several different signal processing techniques learnt at university. After an initial period of familiarisation with EUMETSAT and the particularities of EUMETSAT’s MSG and MTG operational tracking techniques, the trainee should go through the following steps:

• Review existing EUMETSAT’s GEO network antenna pointing and tracking technical documentation (including operational principles);
• Familiarisation with the technical documentation addressing conical scan an alike technique;

• Analyse the feasibility and expected performance of the conscan techniques when applied to the tracking of MSG or MTG spacecraft in the case of one or two spacecraft per aperture;
• Generate a set of operational and non-operational scenarios aiming at measuring the performance margins of the new tracking technique when used for one or two spacecraft;
• Generate (MatLab and/or C++) the required test tools in order to run the selected operational and non-operational scenarios;
• Evaluate the performance of such systems under the different scenarios;
• Generate corresponding reports and Technical Notes Generate along with a final technical report.

• Have the ability to work effectively in English;
• Be computer literate;
• Be intrinsically motivated and curious about the internship subject;
• Be able to work independently and collaboratively;
• Have the ability to take the initiative in researching ideas;
• Have the ability to collect, collate, conceptualize and present information clearly.

Additional specific requirements:

• Good understanding of modern signal processing techniques;
• Good understanding of space telecommunications systems;
• Practical experience in either C, C++ or MatLab;
• Practical experience in reading and assessing technical documentation.