*****File RADWAV.DOC I. BACKGROUND On September 11, 1985, the International Cometary Explorer (ICE; originally called ISEE-3) spacecraft made in situ measurements of particles, fields and waves as it traversed the plasma tail of comet Giacobini-Zinner (G-Z). The time of closest approach was approximately 11:02 UT and occurred at a tailward distance of 7,800 km. The spacecraft was inside the bow wave for roughly 3 hours and in the main tail for about 10 min (Brandt et al., 1985; Brandt et al., 1988, and references therein). Data from some of the instruments on the ICE spacecraft are included on this CD-ROM archive for the period 08-14 September, 1985. Ephemeris data giving hourly values of the ICE spacecraft trajectory relative to Earth, Sun and G-Z are included in a separate file. Note that the deviation of the spacecraft from uniform linear motion was negligible during the encounter, so that interpolation of the trajectory is straightforward. References: ---------- Brandt, J.C., M.B. Niedner, and T. von Rosenvinge, "The ICE Project," Adv. Space Res., v.5, 3-16, 1985. Brandt, J.C., "The International Cometary Explorer (ICE) Mission to Comets Giacobini-Zinner and Halley" in "Space Missions to Halley's Comet", p. 99-115, R. Reinhard, B. Battrick (Editors), ESA SP-1066, ESA Publications Division, Noordwijk, The Netherlands, ISBN 0379 6566, 1986. Brandt, J.C., R.W. Farquhar, S.P. Maran, M.B. Niedner, Jr., and T.T. von Rosenvinge, "The International Cometary Explorer" in "Exploration of Halley's Comet. Based on the 20th ESLAB Symposium, held in Heidelberg, F.R.G., 27-31 October 1986," p. 969-980. M. Grewing, F. Praderie, R. Reinhard (Editors). Springer-Verlag, Berlin, F.R.G. 23+984 pp. ISBN 3-540-17344-7 (F.R.G.), ISBN 0-387-17344-7 (USA), 1988. Epstein, G., Hoang, S., Huntzinger, G., Steinberg J. -L., Fainberg, J., Grena, F., Mosier, S.R., and Stone, R.G., "The 3-Dimensional Radio Mapping Experiment (SBH) on ISEE-C", IEEE Trans. on Geoscience Electronics, GE-16, 191, 1978. ========================================================================= II. Radio Mapping Experiment Derived Data This file describes the values of the density and temperature of the electrons measured (radio mapping) during the tail crossing of comet Giacobini-Zinner by ISEE-3/ICE as derived from spectroscopy of the thermal noise spectrum. The data was provided to the National Space Science Data Center (NASA/GSFC) by the Principal Investigator of the Radio Mapping Experiment on ISEE-3/ICE, Dr. Jean-Louis Steinberg of the Observatoire de Paris, Meudon, France. The instrument is described in "The 3-dimensional Radio Mapping Experiment (SBH) on ISEE-C", by R. Knoll, G.Epstein, S.Hoang, G.Huntzinger, J.L.Steinberg, J.Fainberg, F.Grena, S.R.Mosier, and R.G.Stone, IEEE Transactions on Geoscience Electronics, vol. GE-16, No. 3, pp.199-204, July 1978. The data cover the time interval from 10:00 UT to 12:00 UT on September 11, 1985. The time resolution is 54 seconds. Since this method of measuring plasma parameters is relatively new, users of these data are referred to the following papers: N.Meyer-Vernet, P.Couturier, S.Hoang, C.Perche, J.-L. Steinberg, J.Fainberg and C.Meetre, Science, Vol.232, p.370, 1986. N.Meyer-Vernet and C.Perche, J. Geophys. Res., Vol.94, p.2405, 1989. To derive the plasma parameters, it is assumed that the electron distribution function can be approximated by a bi-maxwellian. The density given below is the total electron density (both electron populations) derived from the cut-off frequency of the thermal noise spectrum. The temperature is that of the cold electron population which is always the dominant one. Error bars on the two measured quantities are given in the first of the above mentioned papers. TIME N T HHMMSS cm-3 Deg. K 100000 9.46 0.1585E+06 100054 7.69 0.1585E+06 100148 8.11 0.1585E+06