Dear Kristian

4.2 Compatibility with Other Radio Services and Applications
It is assumed that typical SPS systems will use frequency bands around 2.45 GHz or 5.8 GHz. These bands are already allocated in the ITU-R Radio Regulations to a number of radio services (e.g. civilian and military wireless applications), and are also designated for ISM (industry, science, and medical) and applications such as microwave ovens and wireless LANs [46]. It is mandatory that unwanted emissions – such as carrier noise, harmonics, and spurious and out-of-band emissions of the microwave power-transmission beams – are suppressed sufficiently to avoid interference with other radio services and applications, in accordance with the ITU-R Radio Regulations [46]. This is a serious engineering challenge, given the huge disparity between SPS power levels and those of other radio services. Although the intended bandwidth of the SPS emissions is quite narrow – since an essentially monochromatic wave without modulation will be used – spurious and out-of-band emissions generated by microwave power-transmission beams could substantially degrade the performance of other services and applications, even if received only indirectly.
Of particular concern is interference with radio-astronomical observations, which have a protected band (4.9-5.0 GHz) near the envisioned SPS frequencies or their first harmonic. Radio astronomy has historically increased its sensitivity with time, and in the next decade, major initiatives already begun will enhance the sensitivity by 100 fold over existing instruments. All possible measures need to be taken to protect the corresponding observations, since if they cannot be protected, it would not be possible for an SPS to operate legally under the present ITU regulations. Most experts will agree that even a partially operational SPS will constitute a difficult and unwelcome challenge to radio astronomy, and that the coexistence of radio-astronomical observations with an SPS could be extremely difficult. The same applies for measurements by the Earth-exploration satellite services (e.g., a sub-harmonic of 2.45 GHz is close to 1.4 GHz, used for passive sensing of soil moisture and ocean salinity). In 1997, the ITU initiated work towards an ITU-R Recommendation on wireless power transmission [4], which may be relevant to the interference an SPS could cause to other services.
The possibility of spurious emissions related to tube (e.g. magnetron) failure is a serious concern for radio astronomy and many other services. For example, with 10,000 magnetrons of 100 kW output for the microwave transmission, and assuming a mean time to failure of, say, 30 years for these tubes, it is possible that the average failure rate could be one per day at some point in the life cycle.
Furthermore, the passive thermal radiation of the solar cells of a large number of SPS units is expected to make a substantial zone of the sky, centred on the geostationary orbit, unusable for astronomical observations at essentially all frequencies [47]. This would occur even when the microwave transmission of the SPS towards the Earth was not operational.
In addition to this thermal radiation, the huge solar-cell array would act as a broadband antenna for all radio noise created within the SPS (from switching, out-of-band contributions, etc.). Therefore, such RF noise has to be minimised so as not to degrade operations of radio services and applications.
The apparent angular size of a solar-cell array of 10 km² is close to 1 arc minute (somewhat larger than the angular size of Jupiter), and scattering of unwanted radiation in the atmosphere would substantially extend the affected region. This means that even optical astronomy would be affected in an extended region of the sky, particularly if a large number of SPS units were operational. The substantial loss of observable sky resulting from these wideband emissions (optical, UV, infrared, and radio) needs to be carefully considered.
The requirements of spectral purity (a narrowband signal with very low spurious transmission) and the high efficiency of the transmitter will be opposing constraints. They could be difficult to reconcile, since high-efficiency, high-power transmitters have an inherent problem of non-linearity. This needs to be carefully assessed.
Astronomical Radio Quiet Zones (RQZs) are currently in the process of being implemented in isolated areas in, e.g., Australia, China, and South Africa. This is being done to ensure the regulatory protection of next-generation giant radio telescopes against detrimental manmade radio interference over wide frequency ranges, based on interference threshold levels recommended by the ITU. Currently, regulatory control over the RQZs applies only to ground-based transmissions. However, for the zones to be effective, it is important that they are not exposed to harmful levels of emissions from space. Even when an SPS is operating entirely within its permitted frequency range, with no out-of-band transmissions, the power transmitted within its sidelobes may still be harmful to the operation of broadband radio telescopes in RQZs (and elsewhere). An additional challenge will therefore be to devise solutions to prevent unwanted interference from the SPS into such facilities. These solutions may include aspects of antenna design, location of the SPS, and deployment of mitigation techniques at the radio-astronomy sites.

4.3 Microwave Power Transmission Effects on Human Health
A variety of environmental considerations and safety-related factors should continue to receive consideration because of public concerns about radiowave exposure [48]. Above the centre of the rectenna, the SPS power-flux density will be considerably higher than the currently permissible safety levels for human beings. The ICNIRP (International Commission on Non-Ionising Radiation Protection) and Japan both apply limits of 50 W/m² and 10 W/m² for 2.45 GHz and 5.8 GHz, respectively [49]. The latter level is equal to the power-flux density at the perimeter of the rectenna site [1, Section 4.3]. The corresponding exposure limits for IEEE standards have recently been revised, and they are now closer to the ICNIRP limits (see [50] for details).
Since established safety limits for microwave exposure are exceeded in an area around and above the rectenna during normal operation of the SPS, access would need to be carefully controlled to ensure that environmental safety and health standards are maintained. Under normal operating conditions, the SPS microwave downlink will need to be monitored continuously to ensure that the tightly tuned phased-array techniques and beam control are functioning correctly. Should there be a loss of control, beam-defocusing techniques to disperse the power would need to be applied.
It should be noted that there are currently insufficient data on specific microwave power-transmission effects on human health, and that standards for this particular application are not sufficiently developed. Taking into consideration the importance of this field, more studies are urgently needed regarding human health and its bioeffects (see also more details in [1, Section 4.3]).

5. Radio-Science Issues for Further Studies
The list of issues below is most likely not complete. Depending on the outcome of the questions addressed, other issues may come up. Again, the list is limited to issues of URSI’s scientific domain.
• Can the exposure level of the microwave density at the perimeter of the SPS receiving rectenna site be adequately controlled to avoid exceeding the safety level fixed by international standards?
• What is the impact of rectenna operation on (i) biological systems, such as human beings, birds, insects, and plants, etc.; (ii) airborne vehicles, such as airplanes; and (iii) other electric/electronic equipment and telecommunication networks?
• Can SPS operations be made safe by a precise control of the high-power beam using a pilot signal from the Earth, also taking into account the time delay of the signal?
• The influences of atmospheric refraction, beam defocusing, and of absorption and diffraction by atmospheric gases, aerosols, clouds, and precipitation have to be further examined. Are there other effects caused by the SPS power beam on the environment (magnetosphere, ionosphere, troposphere, etc.) that have not yet been explored?
• What is the impact of SPS electromagnetic emissions – both intended and unwanted (harmonics of the microwave frequency, unexpected and harmful radiation resulting from malfunctions) at microwave frequencies and other related frequencies – on telecommunications, remote sensing, navigation satellite systems, and radio-astronomical observations? What actions can be taken to suppress this unwanted emission? Constraints imposed by the Radio Regulations of the International Telecommunication Union must be taken into account.
• How will reflections of sunlight from the huge satellite structure affect optical-astronomical observations, and how will passive thermal emissions affect radio-astronomical observations?
• What potential is there for damage to the SPS system from space weather?
• What are the consequences of long-term exposure to solar-wind particles, and solar radiation of solar cells and other solid-state devices, for the reliability and costs of SPS systems, taking maintenance and possible replacement into account?
• Will an SPS lead to congestion at the geostationary orbit and to interference with communication satellites?
Even if it is beyond URSI’s scientific domain, the economics of SPS systems have to be examined by competent organisations, since the cost advantage is a crucial issue for the feasibility of the whole SPS concept.
Only some parts of these questions can be addressed by laboratory work, simulations, or system analyses. Tests of the large structures (solar-cell arrays, transmitting antenna, mirrors) in space are mandatory. After successful testing, launching a pilot SPS unit as an operational demonstrator project – presumably with broad international consensus – may be a suitable way to assess the remaining questions. However, before being considered for launch, even for such a pilot unit, all concerns, such as the impact on communications, radio astronomy, Earth observations, and bio-hazards, must be fully addressed.

6. Acknowledgements
This white paper is based on detailed reports on SPS systems prepared by the URSI Inter-Commission Working Group on SPS (SPSICWG) [1]. The URSI Board of Officers is indebted to the members of this Working Group and to R. M. Dickinson, D. Farley, R. Gendrin, and L. Summerer for their help in evaluating this paper.

7. References
1. H. Matsumoto and K. Hashimoto (eds.), Report of the URSI Inter-Commission Working Group on SPS, URSI, 2006, available at http://www.ursi.org.

2. S. Fetter, “Space Solar Power: An Idea Whose Time Will Never Come?,” Physics and Society, 33, 1, 2004, pp. 10-11.

3. A. Smith, “Earth vs. Space for Solar Energy, Round 2,” Physics and Society, 33, 2, 2004, pp. 3-4.

4. International Telecommunication Union, Question ITU-R 210-1/1 on “Wireless Power Transmission,” 2006, http://www.itu.int/itudoc/itu-r/publica/que/rsg1/ 210-1.html.

5. P. Glaser, “Power from the Sun: Its Future,” Science, 162, 22 November 1968.

6a. W. C. Brown, “Satellite Power Stations: A New Source of Energy,” IEEE Spectrum, 10, 3, 1973, pp. 38-47.

6b. W. C. Brown, “The History of Power Transmission by Radio Waves,” IEEE Transactions on Microwave Theory and Techniques, MTT-32, 1984, pp. 1230-1242.

7. US Department of Energy and NASA, “Satellite Power System, Concept Development and Evaluation Program, Reference System Report,” October 1978 (published January 1979).

8. J. C. Mankins, “A Fresh Look at Space Solar Power: New Architectures, Concepts and Technologies,” Acta Astronautica, 41, 4-10, 1997, pp. 347-359.

9. H. Feingold, et al., “Evaluation of Comparison of Space Solar Power Concepts,” IAC-02-R.1.08, IAF, 2002.

10. W. Seboldt, M. Klimke, M. Leipold, and N. Hanowski, “European Sail Tower SPS Concept,” Acta Astronautica, 48, 5-12, 2001, pp. 785-792.

11. L. Summerer, “Solar Power from Space – European Strategy in the Light of Global Sustainable Development,” ESA SPS Programme Plan 2003/2005, GS03.L36, July 2003, http://www.esa.int/gsp/ACT/doc/ESA_SPS_ProgrammePlan2_06.pdf.

12. H. Matsumoto, N. Kaya, I. Kimura, S. Miyatake, M. Nagatomo, and T. Obayashi, “MINIX Project Toward the Solar Power Satellite – Rocket Experiment of Microwave Energy Transmission and Associated Nonlinear Plasma Physics in the Ionosphere,” ISAS Space Energy Symposium, 1982, pp. 69-76.

13. N. Kaya, H. Matsumoto, and R. Akiba, “Rocket Experiment METS Microwave Energy Transmission in Space, Space Power, 11, 3-4, 1992, pp. 267-274.

14. M. Shimokura, N. Kaya, N. Shinohara, and H. Matsumoito, “Point-to-Point Microwave Power Transmission Experiment, Trans. Institute of Electric Engineers Japan, 116-B, 6, 1996, pp. 648-653 (in Japanese).

15. H. Matsumoto and T. Kimura, “Nonlinear Excitation of Electron Cyclotron Waves by a Monochromatic Strong Microwave: Computer Simulation Analysis of the MINIX Results,” Space Power, 6, 1986, pp. 187-191.

16. H. Matsumoto, “Numerical Estimation of SPS Microwave Impact on Ionospheric Environment,” Acta Astronautica, 9, 1982, pp. 493-497.

17. M. Nagatomo and K. Itoh, “An Evolutionary Satellite Power System for International Demonstration in Developing Nations,” Space Power, 12, 1993, pp. 23-36; also at http://www.spacefuture.com/archive/an_evolutionary_satellite_power_system_for_international_demonstration_in_developing_nations.shtml

18. N. Shinohara, Y. Hisada, M. Mort, and JAXA SSPS WG4 Team, “Request and Roadmap for Microwave Power Transmission System of Space Solar Power System (SSPS),” Proc. of IAF2005, Japan, 2005.

19. Y. Kobayashi, T. Saito, K. Ijichi, and H. Kanai, Proc. of the 4th Int. Conf. on Solar Power from Space – SPS ‘04, July 2004, Granada, Spain, ESA SP-567, December 2004.

20. “Special Sections on SSPS,” Radio Science Bulletin, Nos. 310 and 311, 2004.

21. Proc. of the 4th Int. Conf. on Solar Power from Space – SPS ‘04, July 2004, Granada, Spain, ESA SP-567, December 2004.

22. R. M. Dickinson and W. C. Brown, “Radiated Microwave Power Transmission System Efficiency,” NASA TM 33-727, JPL, CIT, Pasadena, CA, May 15, 1975.

23. National Research Council, Laying the Foundation for Space Solar Power: An Assessment of NASA’s Space Solar Power Investment Strategy, Washington, DC, USA, National Academy Press, 2001.

24. NASA – Marshall Space Flight Center, Press Release 98-190: http://www.msfc.nasa.gov/news/news/ releases/1998/98-190.html.

25. H. Cikanek, “Innovative Aerospace Propulsion Systems an Technologies,” NASA Glenn Research Center, 2-4 April 2000, Report No. 216-433-6196, http://www.aero-space.nasa.gov/ events/home&home/glenn/invasp/sld003.htm.

26. ESA General Studies Programme, “System Concepts, Architectures and Technologies for Space Exploration and Utilisation (SE&U Study), Executive Summary,” Contract 127/98/NL/JG(SC), http:// www.esa.int/SPECIALS/GSP/SEMTG70P4HD_0.html.

27. http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/serve.cgi.

28. V. Blandow, P. Schmidt, W. Weindorf, M. Zerta, and W. Zittel, “Earth and Space-Based Power Generation Systems – A Comparison Study,” Final Report 17682/03/NL/EC, ESA final report – LBST, 2004.

29. L. Summerer, M. Vasile, R. Biesbroek, and F. Ongaro, “Space and Ground Based Large Scale Solar Power Plants – European Perspective,” IAC-03/R.1.09, 2003.

30. M. Imaizumi, K. Tanaka, S. Kawakita, T. Sumita, H., Naito, and S. Kuwajima, “Study on Power Generation System for a Space Photovoltaic Power Satellite,” Proceedings of 48th Space Sciences and Technology Conference, 2004, pp. 111-115.

31. G. A. Landis, “Reinventing the Solar Power Satellite,” NASA/TM-2004-212743, 2004, pp. 1-30.

32. S. Kawasaki, “A Unit Plate of a Thin Multilayered Active Integrated Antenna for Space Solar Power System, Radio Science Bulletin, No. 310, 2004, pp. 15-22.

33. N. Shinohara, H. Matsumoto, and K. Hashimoto, “Solar Power Station/Satellite (SPS) with Phase Controlled Magnetrons,” IEICE Trans. Electron., E86-C, 2003, pp. 1550-1555.

34. K. Nanokaichi, N. Shinohara, S. Kawasaki, T. Mitani and H. Matsumoto, “Development of Waveguide-Slot-Fed Active Integrated Antenna for Microwave Power Transmission,” Proceedings of the XXVIIIth General Assembly of International Union of Radio Science (URSI), New Delhi, India, October 23-29, 2005, D08.4 (0950).

35. J. Zbitou, M. Latrach, and S. Toutain, “Hybrid Rectenna and Monolithic Integrated Zero-Bias Microwave Rectifier,” IEEE Transactions on Microwave Theory and Techniques, 54, 2006, pp. 147-152.

36. W. C. Brown, “Electronic and Mechanical Improvement of the Receiving Terminal of a Free-Space Microwave Power Transmission System,” Wayland, MA, Raytheon Company, Tech. Report PT-4964, NASA Report No. CR-135194, NASA Contract No. NAS 3-19722, August 1977, p. 66.

37. J. O. McSpadden, L. Fan, and K. Chang, “Design and Experiments of a High-Conversion-Efficiency 5.8-GHz Rectenna,” IEEE Transactions on Microwave Theory and Techniques, MTT-46, 12, December 1998, pp. 2053-2060.

38. N. Shinohara, H. Matsumoto, A. Yamamoto, H. Okegawa, T. Mizuno, H. Uematsu, H. Ikematsu, and I. Mikami, “Development of High Efficiency Rectenna at mW input,” Technical Report of IEICE, SPS2004-08 (2005-04), pp. 15-20 (in Japanese).

39. N. Shinohara and H. Matsumoto, “Dependence of dc Output of a Rectenna Array on the Method of Interconnection of its Array Elements,” Electrical Engineering in Japan, 125, 1, 1998, pp. 9-17.

40. J. F. Drake, M. Swisdak, H. Che, and M. A. Shay, “Electron Acceleration from Contracting Magnetic Islands During Reconnection,” Nature, October 5, 2006.

41. S. A. Cummer, Y. Zhai, W. Hu, D. M. Smith, L. I. Lopez, and M. A. Stanley, “Measurements and Implications of the Relationship Between Lightning and Terrestrial Gamma Ray Flashes,” Geophys. Res. Lett., 32, 2005, L08811, doi:10.1029/2005GL022778.

42. T. R. Robinson, T. K. Yeoman, and R. S. Dhillon, “Environmental Impact of High Power Density Microwave Beams on Different Atmospheric Layers,” Radio and Space Plasma Physics Group Tech. Rep. 63, ESA Contract number: 18156/04/NL/MV, Leicester University, UK, 2004.

43. F. W. Perkins and R. G. Roble, “Ionospheric Heating by Radio Waves: Predictions for Arecibo and the Satellite Power Station,” J. Geophys. Res., 83, A4, 1977, pp. 1611-1624.

44. G. M. Batanov, I. A. Kossyi, and V. P. Silakov, Plasma Physics Reports, 28, 3, 2002, pp. 204-228 (translated from Fizika Plazmy, 28, 3, 2002, pp. 229-256).

45. J. Lavergnat and M. Sylvain, Radio Wave Propagation, Principles and Techniques, New York, John Wiley and Sons, 2000.

46. International Telecommunication Union, Radio Regulations, edition of 2004.

47. A. R. Thompson, “Effects of a Satellite Power System on Ground-Based Radio and Radar Astronomy,” Radio Science, 16, 1981, pp. 35-45.

48. J. C. Lin, “Space Solar-Power Stations, Wireless Power Transmissions, and Biological Implications,” IEEE Microwave Magazine, March 2002, pp. 36-42.

49. ICNIRP, “Guidelines for Limiting Exposure to Time-Varying Electric, Magnetic, and Electromagnetic Fields (Up to 300 GHz),” Health Physics, 74, 1998, pp. 494-522.

50. J. C. Lin, The New IEEE Standard for Human Exposure to Radio-Frequency Radiation and the Current ICNIRP Guidelines, Radio Science Bulletin, No. 317, 2006, pp 61-63.

8. Appendix 1: URSI White Papers
URSI (International Union of Radio Science) white papers are documents issued by URSI scientific experts on controversial subjects involving aspects of radio science. They may be proposed to the URSI Board of Officers by an URSI Member Committee, an URSI Commission, an URSI Standing Committee, an URSI Working Group, or in response to a request to URSI by another body.
Where the issuance of a white paper is determined to be necessary, the appropriate mechanism for preparing it is agreed to between the URSI Secretariat and the URSI Board of Officers. Once a draft URSI white paper has been prepared, the URSI Secretariat forwards this to the members of the Board of Officers and to the URSI Member Committees and Commissions for review. All comments received by the URSI Secretariat are then either incorporated directly into the white paper, if appropriate, or are forwarded to the author(s) for consideration. The URSI Secretariat acts as a liaison throughout this process. The final version of the URSI white paper is then sent to the members of the URSI Board of Officers for approval. Finally, the white paper is distributed to ICSU, appropriate scientific unions and bodies, and is published in the Radio Science Bulletin.
The white paper is the responsibility of URSI. However, it does not necessarily reflect all the views of the individual URSI Member Committees nor of the Commissions.

9. Appendix 2: the ten Scientific Commissions of URSI and their Terms of Reference
9.1 Commission A: Electromagnetic Metrology, Electromagnetic Measurements, and Standards
The Commission promotes research and development in the field of measurement standards, in calibration and measurement methodologies, and the intercomparison of such. Areas of emphasis are:

(a) the development and refinement of new measurement techniques;

(b) primary standards, including those based on quantum phenomena;

(c) realization and dissemination of time and frequency standards;

(d) characterization of the electromagnetic properties of materials;

(e) electromagnetic dosimetry.

The Commission fosters accurate and consistent measurements needed to support research, development, and exploitation of electromagnetic technologies across the spectrum.
9.2 Commission B: Fields and Waves, Electromagnetic Theory and Applications
The interest of Commission B is fields and waves, encompassing theory, analysis, computation, experiments, validation, and applications. Areas of emphasis are:

(a) Time-domain and frequency-domain phenomena;

(b) Scattering and diffraction;

(c) General propagation including waves in specialised media;

(d) Guided waves;

(e) Antennas and radiation;

(f) Inverse scattering and imaging.

The Commission fosters the creation, development, and refinement of analytical, numerical, and measurement techniques to understand these phenomena. It encourages innovation and seeks to apply interdisciplinary concepts and methods.

9.3 Commission C: Radio-Communication Systems and Signal Processing
The Commission promotes research and development in:

(a) Radio-communication and telecommunication systems;

(b) Spectrum and medium utilisation;

(c) Information theory, coding, modulation, and detection;

(d) Signal and image processing in the area of radio science.

The design of effective radio-communication systems must include scientific, engineering, and economic considerations. This Commission emphasises research into the scientific aspects, and provides enabling technologies to other areas of radio science.

9.4 Commission D: Electronics and Photonics
The Commission promotes research and reviews new developments in:

(a) Electronic devices, circuits, systems, and applications;

(b) Photonic devices, systems, and applications;

(c) Physics, materials, CAD, technology, and reliability of electronic and photonic devices down to nanoscale including quantum devices, with particular reference to radio science and telecommunications.

The Commission deals with devices for generation, detection, storage, and processing of electromagnetic signals together with their applications from the low frequencies to the optical domain.
9.5 Commission E: Electromagnetic Noise and Interference
The Commission promotes research and development in:

(a) Terrestrial and planetary noise of natural origin, seismic-associated electromagnetic fields;

(b) Man-made noise;

(c) The composite noise environment;

(d) The effects of noise on system performance;

(e) The lasting effects of natural and intentional emissions on equipment performance;

(f) The scientific basis of noise and interference control, electromagnetic compatibility;

(g) Spectrum management.

9.6 Commission F: Wave Propagation and Remote Sensing (Planetary Atmospheres, Surfaces, and Subsurfaces)
The Commission encourages:

(a) The study of all frequencies in a non-ionised environment:

(i) wave propagation through planetary, neutral atmospheres, and surfaces

(ii) wave interaction with the planetary surfaces (including land, ocean, and ice), and subsurfaces,

(iii) characterisation of the environment as it affects wave phenomena;

(b) The application of the results of these studies, particularly in the areas of remote sensing and communications;

(c) The appropriate co-operation with other URSI Commissions and other relevant organisations.
9.7 Commission G: Ionospheric Radio and Propagation (Including Ionospheric Communications and Remote Sensing of Ionised Media)
The Commission deals with the study of the ionosphere in order to provide the broad understanding necessary to support space and ground-based radio systems. Specifically, the Commission addresses the following areas:

(a) Global morphology and modelling of the ionosphere;

(b) Ionospheric space-time variations;

(c) Development of tools and networks needed to measure ionospheric properties and trends;

(d) Theory and practice of radio propagation via the ionosphere;

(e) Application of ionospheric information to radio systems.

To achieve these objectives, the Commission co-operates with other URSI Commissions, corresponding bodies of the ICSU family (IUGG, IAU, COSPAR, SCOSTEP, etc.) and other organisations (ITU, IEEE, etc.).
9.8 Commission H: Waves in Plasmas (Including Space and Laboratory Plasmas)
The goals of the Commission are:

(a) To study waves in plasmas in the broadest sense, and in particular:

(i) the generation (i.e. plasma instabilities) and propagation of waves in plasmas,

(ii) the interaction between these waves, and wave-particle interactions,

(iii) plasma turbulence and chaos,

(iv) spacecraft-plasma interaction ;

(b) To encourage the application of these studies, particularly to solar/planetary plasma interactions, space weather, and the exploitation of space as a research laboratory.
9.9 Commission J: Radio Astronomy (including Remote Sensing of Celestial Objects)
(a) The activities of the Commission are concerned with observation and interpretation of all radio emissions and reflections from celestial objects.

(b) Emphasis is placed on:

(i) the promotion of technical means for making radio-astronomical observations and data analysis,

(ii) support of activities to protect radio-astronomical observations from harmful interference.

9.10 Commission K: Electromagnetics in Biology and Medicine
The Commission is charged with promoting research and development in the following domains:

(a) Physical interaction of electromagnetic fields* with biological systems;

(b) Biological effects of electromagnetic fields;

(c) Mechanisms underlying the effects of electromagnetic fields;

(d) Experimental electromagnetic fields exposure systems;

(e) Assessment of human exposure to electromagnetic fields;

(f) Medical applications of electromagnetic fields.

* (frequency range from static to terahertz)

More information about URSI can be obtained from its Web pages at http://www.ursi.org. 

1URSI (International Union of Radio Science) white papers are documents issued by URSI scientific experts on controversial subjects involving aspects of radio science. Although under the responsibility of URSI, they do not necessarily reflect all the views of individual URSI Member Committees nor Commissions (see Appendix 1).