What kind of testing does the RF Payload Systems Laboratories carry out?
The RF Laboratory performs specialised measurements related to RF hardware, from complete systems down to equipment e.g. high power amplifiers (solid state power amplifiers - SSPA or travelling wave tube amplifier - TWTA), and individual component such as monolithic microwave integrated circuits (MMICs) or transistors.
The Laboratory carries out life testing of RF systems, and by extension uses dedicated facilities to investigate various undesirable effects of prolonged RF operations. These include 'multipaction', where the high electric field of a signal in vacuum accelerates electrons, which can damage RF devices, and the similar phenomenon of 'RF Corona' where residual gases are ionised by the RF signal, causing signal reflection and sometimes permanent degradation.
It also tests ultra-precise timing and frequency systems at the heart of satellite navigation systems, such as atomic clocks and ultra-stable oscillators.
The Radio Navigation Laboratory provides test support to Galileo and other core navigation activities, including the European Geostationary Navigation Overlay Service (EGNOS), a space- and ground-based system to augment the accuracy of current satellite navigation constellations over Europe.
It evaluates the performance of new types of products related to Galileo, GPS or EGNOS, offering independent certification of receivers. It uses a range of satellite navigation simulators equipped with an interference generator to assess mitigation strategies and test ground segment receivers.
The Laboratory monitors actual EGNOS performance on a real-time basis, generating data for public users of the overlay service. It also analyses digitally captured signals, isolates navigation signals from individual satellites using a high-gain antenna and makes in-the-field measurements.
Finally, it is operating a formation flying test bed, to simulate the use of satellite navigation for real-time autonomous operations of combined spacecraft formations.
The RF Remote Sensing Laboratory performs evaluations and simulations related to RF remote sensing instruments. Both active sensors – where a radio beam is directed towards a target and the resulting backscatter recorded – and passive sensors – which simply detect naturally occurring RF signals – are subjects of study.
Examples of active sensors include SARs, scatterometers, radar altimeters, rain radar and ice sounders. Passive sensors include radiometers and a promising ESA-developed technology called Passive Reflectometry and Interferometry System (PARIS) which detects navigation signals reflected off the Earth's surface.
Testing is performed using customised software and simulators, but sensor hardware like transmit-receive modules, antenna panels and central electronic units may also be put through their paces.
Spread across two ESA sites, ESTEC in the Netherlands and ESRIN in Italy, the ESA Telecom Laboratory assesses innovative telecommunication technologies and techniques at the system and subsystem level.
The ESTEC side of the Laboratory supports ESA Telecom's R&D activities, including the evaluation of new satellite communication (satcom) systems and products from industry, including technical support for companies in ESA's business incubator (Technology Transfer). It is active in telecom standardisation efforts by supporting the technical working groups and facilitating the validation of new concepts.
Other activities include network simulation and emulation used to develop satcom system architectures and assessment of new concepts such as Space based Automatic Identification Systems (AIS) allowing global ship tracking from orbit.
The ESRIN office of the Laboratory supports the telemetry requirements of the Earth Observation Directorate, includes simulation and experimental assessment of high speed data links, and providing industry with access to telecom infrastructure for testing, including integration of Earth observing and satcom technologies.
Last update: 24 March 2010