The chairman of the day Prof.dr.ir. Mark Bentum (UT) began with an Introduction on URSI. URSI was founded in 1922 with the Union of the International Council of Science. In the URSI = Union Radio-Scientifique Internationale, 40 countries were represented, including the Dutch URSI committee. Then the main line in the radio-technical developments of Radio Science through time and worldwide was presented, all within the context of the URSI .The headquarters of URSI is allocated in Ghent.

Every 3 years the "General Assembly (GA)" is organised, a gathering of 1000 to 2000 radio scientists, coming from all continents. About 600 "Conference papers" are, presented and discussed. The past GA was the "32nd General Assembly 2018" , organised in Montreal Canada, attended by about 1,200 participants (scientists).

Based on the classification to committees within the URSI, it is indicated, which presentations are now presented at this KIVI-TC meeting. A number of presentations focus on the development of the future radio telescope in South Africa and Australia: The Square Kilometre Array (SKA)(Brochure Dutch contribution Astron)

Within the framework of LOFAR (Low frequency Array), the first speaker Prof.dr Stefan Wijnholds (Astron) addressed the development of a measurement instrument using a drone, LOFAR consists of 51 base stations, each with large numbers of antennas over an area of 150m to 1000m. The 51 stations together, covers an area of 1200km in Europe.

To measure the field strength and magnetic field above antennas, a drone is used. Fitting a dipole antenna under a drone seems simple, but to obtain relevant stable measurement results (E and H fields) from antennas, a lot was involved. Both the material use of the rotor blades and the construction (frame) of the drone, as well as the suspension of the antenna, turned out to partly determine the accuracy of the measurement results, as well as the actual position of the dipole antenna during flight. By compensating this deviation software-wise (seemingly shorter antenna on the drone), this could be solved.

After this, it proved possible to accurately determine E and H pattern of the antennas on the ground. The drone requires a safe Flightplan, this is achieved with so-called "Waypoints" in "square loops" of 300m at an altitude of 92m. The actual position (before calibration) proved insufficient with an accuracy of +/- 1m and could only be increased to 1cm with additional GPS information from the antenna positions. This developed system could make an important contribution to SKA, where it involves more than 30,000 antennas/cables in the Australian desert.

The second speaker, Dr Ramiro Serra (TU/e), investigated the EMC effects on increasingly smaller chips. It turns out that in-chip signal transmission, which takes place both analogue and digital simultaneously, generates interference, which undesirably affects propagation.

Using an efficient approach with EM modelling and various type of implementations at the transitions on the chip, the scientific research was carried out, from which it was found, that using SiO2 (a grain of sand) as isolation, is crucial to obtain an embedded "Ground-Signal-Ground" structure, which can lead to manageable interference. The results of the research on equal radial symmetric structures, can be extrapolated to other implementations. These studies were carried out in close cooperation with NXP.

The third speaker Dr Richard Fallows (Astron) put into focus, how to achieve a new generation of radio telescopes with his presentation on "A Comprehensive Tool for Space Weather Observation", again within the framework of the Low-Frequency Array (LOFAR). An International LOFAR Telescope (ILT) consists of core-stations, projected widely around the world. Each core-station has a diameter of 4 km and the signals can be combined as an interferometer, bundling and stacking the signals on top of each other. It has now become possible to observe and track activities on the sun (Solar Wind) and measure the effects and indicate the impact on Earth.

After the break, the fourth speaker Prof.dr.ir. Frank Leferink UT with a nice example of radio control with EM interference = EMC (Electro Magnetic Comptability). It turned out, that the EMC costs for US warships increase exponentially because of the (many) EMC standards in the USA. This excess of EMC rules and standards is no longer a good basis for complex systems and will certainly not suffice in the future. By using common sense and compartmentalising (TR) spaces or dividing areas by function, EM levels are determined based on risk management and it becomes possible to control the effects of EMC. The new EMC directive planned for 2019 will therefore be "Risk-based" and suitable for any (unique) EM environment. A real EMC challenge is the operating room in a hospital, where wireless connections are needed for sensors, monitoring and remote control, but where mobile phones are also brought in. The new guideline will be discussed at the International Symposium EMC Europe 2018, which will be held on 27-30 August 2018 in Amsterdam (see annex for details).

The fifth speaker, Dr.ir. Peter Maat (Astron), presented "Long distance RF over fibre technology for radio Telescopes" and showed a clever example of cost reduction for the procurement, procurement and production of the modules to be developed for the many RF links to the 130,000 SKA antennas.

The sixth speaker, Ir. Eric Kooistra (Astron), went on from the Gemini FPGA Hardware Platform to develop the hardware unit and racks of the Central Signal Processor (CSP) and, with the FPGA Firmware, gave an insight, how the huge data stream of data is bundled, controlled and stored and can be "read back" for research.

Note: The 6th appendix of the report can be downloaded using the following link 6. Gemini FPGA Hardware Platform for the SKA Low Correlator and Beamformer by Ir. Eric Kooistra Astron

Description

On 13 March, URSI and the KIVI Telecommunications Department will offer a theme evening concerning developments taking place in Radio Science in the Netherlands.

Presentations were previously given at the URSI General Assembly held in Montreal, Canada, in August 2017.

Six speakers from Dutch institutes made presentations at this conference, which will be given again on this evening.

URSI (Union Radio-Scientifique is a Netherlands Member Committee of URSI (Internationale).
URSI is non-governmental and non-profit organisation under the International Council for Science. It is responsible for stimulating and coordinating, on an international basis, studies, research, applications, scientific exchange, and communication in the fields of radio science.

Speaker(s)

Prof.dr.ir. Mark Bentum is an Associate Professor in the Telecommunication Engineering Group at the University of Twente, is now involved with research and education in mobile radio communications. He is a Member of the IEEE, NERG, KIVI and the Dutch Pattern Recognition Society and has acted as a reviewer for various conferences and journals.

Prof.dr. Stefan Wijnholds System Researcher, System Design and Integration ASTRON, R&D Department Extraordinary Associate Professor Electrical and Electronic Engineering University of Stellenbosch.

Dr Ramiro Serra Eindhoven University of Technology and is an assistant researcher in the Telecommunication Engineering group and a guest researcher in the Electrical Energy Systems Group.

Dr Richard Fallows ASTRON

Prof.dr.ir. Frank Leferink University of Twente is supervising High Intensity Radiated Field SynEthetic Environment (HIRF-SE), Power Quality and EMC.

Dr.ir. Peter Maat System Researcher ASTRON in Optical data transport systems

Ir. Eric Kooistra ASTRON

Location

Aristo Utrecht

Brennerbaan 150, 3524 BN Utrecht

Organiser

Telecommunications

URSI

Name and contact details for information

ing R. Julémont-Gerssen tel 0527 651 751

julemont@home.nl

URSI Netherlands

URSI International

URSI Genaral Assembly August, 2017

Astron Netherlands Institute for Radio Astronomy

Documents