NC URSI: National Committee of the Union radio-scientifique internationale
The International Union of Radio Science (Union Radio-Scientifique Internationale, URSI) is structured into various scientific commissions. Switzerland is currently active in six of them:
Commission B (Fields and Waves)
Commission C (Radiocommunication Systems and Signal Processing)
Commission D (Electronics and Photonics)
Commission E (Electromagnetic Environments and Interference)
Commission F (Wave Propagation)
Commission K (Electromagnetics in Biology and Medicine)
The following is a summary of the highlights from several of the active commissions:
Switzerland was represented at the URSI AT-RASC conference held on May 19–24, 2024, in Gran Canaria. Contributions came from several Swiss URSI members and collaborators, underlining the country’s active involvement in the international radio science community.
Commission B – Fields and Waves
Continued research on electromagnetic field measurements, current recordings, high-speed imaging, and X-ray emissions from upward lightning at the Säntis tower has advanced the understanding of the physical mechanism behind the main pulse in Type-1 upward positive lightning flashes.
Theoretical and experimental studies on resonant metaleses for the super-resolution imaging of electromagnetic interference sources have been successfully conducted and validated.
Theoretical investigations explored the relationship between Cartesian and spherical multipole moments, Electromagnetic Time Reversal (EMTR) in anisotropic media, TR-MUSIC (Time Reversal Multiple Signal Classification) for enhanced resolution in imaging applications, including underground landmine detection and EMC interference localization
These results were presented at the URSI AT-RASC confenence in Gran Canaria, the International Conference on Lightning Protection (ICLP) in Dresden and GlobalEM 2024 in Austin.
Research also progressed on the physics of laser-guided lightning discharges using high-repetition-rate, high-power laser systems.
Commission E – Electromagnetic Environments and Interference
On March 27, 2024, an in-person workshop on HEMP and IEMI advances was held at Montena Technology in Rossens, co-organized by URSI Commission E, the IEEE Switzerland EMC/AP/MTT Joint Chapter, Montena Technology, and ETS-Lindgren.
Dr. Mohammad Azadifar (Swiss URSI representative and Chair of the IEEE EMC/AP/MTT Switzerland Chapter) co-led the event.
The keynote speaker was Dr. Carlos Romero (Armasuisse S+T), who also chaired the technical program. Additional talks included:
François Volery (Montena): Design and Applications of Repetitive High-Voltage Generators
Tobias Okech (MPE, UK): Importance of HEMP/IEMI Filter Design for Critical Infrastructure Protection
Elias Le Boudec (EPFL): Experimental Single-Shot Localization of Electrostatic Discharge Paths
Demonstrations of high-voltage equipment and HPEM systems enriched the workshop experience, contributing to discussions on infrastructure protection and the latest advancements in HEMP/IEMI mitigation.
Commission F – Propagation
Activities in 2024 were closely tied to the ongoing preparatory work for WRC-27, and to the contributions to ITU-R Study Group 3 (Radio Propagation) and the European Electronic Communications Committee (ECC).
Swiss expert Dr. Ivica Stevanovic maintained and updated several official software tools and validation datasets associated with ITU-R Recommendations, hosted on the ITU-R SG3 website. These include:
ITU-R P.368-10: Ground-wave propagation (10 kHz – 30 MHz)
ITU-R P.452-18: Interference prediction above 100 MHz
ITU-R P.528-5: Propagation for aeronautical/mobile services (VHF–SHF)
ITU-R P.1546-6: Point-to-area predictions (30 MHz – 4 GHz)
ITU-R P.1812-6: Path-specific propagation (30 MHz – 6 GHz)
ITU-R P.2001-4: Wide-range terrestrial model (30 MHz – 50 GHz)
Commission K – Electromagnetics in Biology and Medicine
Under the leadership of Francesca Apollonio (Chair, 2023–2026 triennium), Commission K continues to promote multidisciplinary research in:
EM field interactions with biological systems
Health and ecological impacts of EM fields
Dosimetry and exposure systems
EM-based diagnostics and therapeutic technologies
Public concern remains high regarding EM exposure safety, while beneficial applications in bioelectronic medicine (e.g., neuroprosthetics, electroceuticals) are rapidly evolving.
Commission K was highly active at AT-RASC 2024, contributing 62 papers out of over 900 submissions.
Preparations are ongoing for AP-RASC 2025 and the URSI General Assembly and Scientific Symposium (GASS) 2026, which will include 12 dedicated sessions and 4 joint sessions from Commission K.
[1] R. Alipio, N. Duarte, and F. Rachidi, “High-frequency transients in buried insulated wires: Transmission line simulations and experimental validation,” Electric Power Systems Research, vol. 237, p. 110993, 2024.
[2] V. Cooray, F. Rachidi, and M. Rubinstein, “An Engineering Model to Represent Positive Return Strokes—An Extension of the Modified Transmission Line (MTL) Model,” Atmosphere, vol. 15, no. 11, p. 1265, 2024.
[3] J. M. Chaffin et al., “Mountaintop Gamma Ray Observations of Three Terrestrial Gamma?Ray Flashes at the Säntis Tower, Switzerland With Coincident Radio Waveforms,” JGR Atmospheres, vol. 129, no. 2, Jan. 2024, doi: 10.1029/2023jd039761.
[4] H. Karami, A. Koch, C. Romero, M. Rubinstein, and F. Rachidi, “Landmine detection using electromagnetic time reversalbased methods: 1. classical TR, iterative TR, DORT and TR-MUSIC,” Radio Science, vol. 59, no. 10, pp. 1–13, 2024.
[5] T. Produit, J. Kasparian, F. Rachidi, M. Rubinstein, A. Houard, and J.-P. Wolf, “Physics and technology of laser lightning control,” Reports on Progress in Physics, vol. 87, no. 11, p. 116401, 2024.
[6] D. Li et al., “Propagation Effects of Slanted Narrow Bipolar Events: A Rebounding?Wave Model Study,” JGR Atmospheres, vol. 129, no. 14, Jul. 2024, doi: 10.1029/2023jd040497.
[7] E. Le Boudec, N. Mora, F. Rachidi, M. Rubinstein, and F. Vega, “Time-reversed electromagnetic fields in anisotropic media,” Optics Letters, vol. 49, no. 7, pp. 1820–1823, 2024.
[8] E. Le Boudec, H. Karami, N. Mora, F. Rachidi, M. Rubinstein, and F. Vega, “Spatiotemporal energy?density distribution of time?reversed electromagnetic fields,” IET Science Measure & Tech, vol. 18, no. 9, pp. 471–482, Nov. 2024, doi: 10.1049/smt2.12196.
[9] E. Le Boudec et al., “The time-domain Cartesian multipole expansion of electromagnetic fields,” Scientific Reports, vol. 14, no. 1, p. 8084, 2024.
[10] T. Oregel-Chaumont, A. Šunjerga, P. Hettiarachchi, V. Cooray, M. Rubinstein, and F. Rachidi, “Direct observations of X-rays produced by upward positive lightning,” Scientific Reports, vol. 14, no. 1, p. 8083, 2024.
[11] A. Sunjerga, M. Rubinstein, D. Poljak, M. Despalatovi?, G. Petrovi?, and F. Rachidi, “High-frequency response of a hemispherical grounding electrode,” Electric Power Systems Research, vol. 226, p. 109877, 2024.
[12] V. Cooray, G. Cooray, M. Rubinstein, and F. Rachidi, “Heuristic Estimation of the Vacuum Energy Density of the Universe: Part II-Analysis Based on Frequency Domain Electromagnetic Radiation,” 2024.
[13] A. Ragusa, P. A. Wouters, H. Sasse, A. Duffy, F. Rachidi, and M. Rubinstein, “Electromagnetic time reversal for online partial discharge location in power cables: influence of interfering reflections from grid components,” IET Science, Measurement & Technology, vol. 18, no. 9, pp. 483–490, 2024.
[1] H. Karami; M. Rubinstein; F. Rachidi-Haeri; A. Koch; C. Romero, High-Resolution Time Reversal Multiple Signal Classification for Enhanced Landmine Localization, Global Electromagnetics International Conference (GlobalEM 2024), Austin, TX, 2024-07-14 – 2024-07-19.
[2] S. Tkachenko; F. Middelstaedt; R. Vick; F. Rachidi, High-Frequency Electromagnetic Field Coupling to Infinite Single and Double Helical Wires, Global Electromagnetics International Conference (GlobalEM 2024), Austin, TX, 2024-07-14 – 2024-07-19.
[3] E. Le Boudec; F. Rachidi-Haeri; F. Vega; H. Karami, Towards low-cost single-port imaging with a resonant metalens, Global Electromagnetics International Conference (GlobalEM 2024), Austin, TX, 2024-07-14 – 2024-07-19.
[4] H. Karami; C. Romero; A. Koch; M. Rubinstein; F. Rachidi-Haeri, High Resolution Time-Reversal Imaging: A Comparison between Time-Reversal MUSIC and DORT, 4th URSI Atlantic Radio Science Meeting (AT-RASC), Gran Canaria, Spain, 2024-05-19 – 2024-05-24.
[5] E. Le Boudec; M. Rubinstein; F. Rachidi-Haeri; F. Vega, Inexpressibility of fields radiated by Cartesian multipole moments as spherical harmonics in anisotropic media, 4th URSI Atlantic Radio Science Meeting, Gran Canaria, Spin, 2024-05-19 – 2024-05-24.
[6] L. Pini; D. Baissac; G. Nicora; M. Barle; E. Mansouri et al., Application of the Smorgonskiy Method for the Estimation of Upward Lightning Incidence on Tall Towers Using WWLLN Data – Preliminary Results, 37th International Conference on Lightning Protection, Dresden, Germany, 2024-09-01 – 2024-09-07.
A tutorial on lightning was organized:
F. Rachidi and M. Rubinstein, Lightning: Basics, Incidence, and Location Techniques. Tutorial given at the Global Electromagnetics International Conference (GlobalEM 2024), Austin, TX, 2024.
A Plenary Session presentation was given:
F. Rachidi and M. Rubinstein, Säntis Lightning Research Facility: Recent Developments and Findings, presented at the Global Electromagnetics International Conference (GlobalEM 2024), Austin, TX, 2024.
Special Sessions were organized:
The Swiss URSI commissions C and E organized a special session on lightning electromagnetics for the URSI AP-RASC Conference to be held in Sydney, Australia, Aug 17-22, 2025.
The Swiss URSI commissions C and E organized a special session on Electromagnetic Time Reversal for the URSI AP-RASC Conference to be held in Sydney, Australia, Aug 17-22, 2025.