As regards the Review of Radio Science (RRS), the Commission A Vice-Chair, Dr. Motohisa Kanda, is the Commission A Editor for RRS. Commission A will contribute seven chapters to the RRS , namely:
A large part of the activities of the Commission consists in the realization of the biennial Conferences on Precision Electromagnetic Measurements (CPEM), for which URSI Commission A is one of the main permanent sponsors. The conference has received an outstanding reputation over more than three decades as an international forum for precision electromagnetic measurements. It is held every two years either in the USA (or Canada), or in a country outside North America. Traditionally, it is organized mainly by members of the hosting national institute of metrology, but individual members of URSI are involved in a considerable part. The Commission A Chairman is a member of the CPEM Executive Committee.
CPEM'94 took place in Boulder, CO, USA from 27 June to 1 July 1994. In 38 sessions, more than 270 papers were presented. A large part of the sessions was dedicated to topics such as cesium beam and optical frequency standards and metrology and time keeping and transfer as well as to the different aspects of quantum metrology and fundamental constants. About 60 papers covered topics such as microwave and millimeter wave metrology, noise metrology, time domain measurements, antennas and EMC network analysis as well as material measurements. A session on lightwave communication metrology also aroused lively interest. The papers were well received, followed by a considerable amount of discussions, which indicated the significance of the themes chosen. The conference was very well attended by more than 470 participants, this also showed the increasing interest of companies and national calibration services in precision electromagnetic metrology. Sixteen Young Scientists from nine different countries were given financial travel support.
CPEM'96 will be held in the Civic Hall of Braunschweig, Germany, from 17 to 20 June 1996. Up to now, over 370 papers from 51 countries have been submitted. URSI members (including the Commission A Chair) are involved in the organization as well. About 10 RF sessions with 70 papers are scheduled. Compared to the 1994 conference, the number of submitted papers on electric quantum standards and frequency standards has considerably increased. New sessions are those on novel sensors and automated measurement methods and their applications in precision metrology. Plenary speakers will be Klaus von Klitzing (Stuttgart, Germany), Konstantin K. Likharev (Stony Brook, USA) and Herbert Walther (Munich, Germany).
As the URSI representative to the Comité Consultatif d'Electricité (CCE), the Commission A Chairman took part in the meeting of the Working Group on Radiofrequency Quantities of the CCE, which was held at the BIPM in Sèvres, France, on 12 and 13 June 1995. This Group took over URSI responsibility in 1965. Since 1992, eight comparison measurements of different RF quantities covering frequencies up to 40 GHz have been completed, and good coincidence between measurements of the different national institutes of metrology has been found. Thirteen comparison measurements are continuing, to maintain further the equivalence between the primary RF measurement standards of national metrology institutes. In the future, key multilateral comparisons have to be identified and the intervals at which they should be repeated, in order to limit the comparisons to a economically justifiable number. A detailed report of comparisons will be given by L. Erard in the Session A2 of the forthcoming General Assembly of URSI in Lille.
The Comité Consultatif pour la Définition de la Seconde (CCDS) held at the BIPM its 12th meeting from 24 to 26 March 1993 and its 13th meeting on 12 and 13 March 1996. Representatives of Commission A were present at both meetings. The discussions focussed on the optimum use of available means for international synchronization of time-scales, namely satellite time transfer via GPS, GLONASS and telecommunication satellites. The driving force is the increasing need of synchronization between national realizations of UTC, the present goal being 100 ns. Another item has been to promote the development, evaluation and operation of primary frequency standards which should allow to maintain the scale unit of International Atomic Time TAI as close as possible to the SI second. It was particularly welcomed that evaluations of four new primary standards have been made available recently, CS3 of PTB, NIST-7 of NIST, FO1 of LPTF, France, and MCS102 of VNIIFTRI, Russia. In 1996 it was decided that the frequency of primary clocks should be corrected for the AC Stark-effect due to the electric fields of the thermal background radiation. This effect has been predicted to yield a frequency shift of as much as -1,7x10-14 at room temperature. In the past no correction had been applied as no experimental verification of the effect had been available, a situation which has not changed until now.
Other Commission A related activities were reported at the 11th International Zurich Symposium and Technical Exhibition on Electromagnetic Compatibility, which was held at the Swiss Federal Institute of Technology, Zurich, Switzerland, from 7 to 9 March 1995. There were about 400 participants who attended the thematic technical sessions, workshops, tutorial lectures, open meetings, technical exhibition, technical excursions, and social programs which included guests' excursions to pleasant Swiss resorts. About 120 papers were presented in the thematic technical sessions, which covered in the technical areas of transient effects, EMC applications, power systems, transmission lines, EMC standards, spectrum management, EMC emission and immunity testing, EM field hazards, numerical techniques, lighting, EMP, shielding and coupling, ESD dynamics and others. Perhaps more technical exciting Commission A related activities were reported at the International Symposium on Electromagnetic Compatibility that was held at the University Of Rome "La Sapienza", Rome, Italy, from 13 to 16 September 1994. There were about 700 participants who attended 26 technical sessions and several workshops and made about 100 oral presentations and 80 poster presentations. The technical sessions covered the technical areas in EMC standards and regulations, interconnecting and packaging structures, human exposure to EM fields, lighting, EMC standard testing, PCB and chip design, power systems, antenna and communication systems, modelling techniques, measurement and instrumentation, anechoic chambers and TEM cells, cables, EMC automotive, shielding, transients, propagation and coupling in transmission lines. The workshop provided a forum for the discussion on technical and scientific perspectives of strategic interest for EMC and EMC activities supported by the Commission of the EC.
A considerable amount of the work of Commission A is the organization of four scientific sessions and 10 joint scientific sessions with Commissions B, D, E, F and K in the forthcoming General Assembly of URSI. About 140 papers will be presented.