| タイトル | Time delay occultation data of the Helios spacecrafts and preliminary analysis for probing the solar corona |
| 著者（英） | Esposito, P. B.; Lueneburg, E.; Zygielbaum, A. I.; Hansen, R. T.; Martin, W. L.; Hansen, S. F.; Edenhofer, P. |
| 著者所属（英） | Jet Propulsion Lab., California Inst. of Tech.|Deutsche Forschungs- und Versuchsanstalt fuer Luft- und Raumfahrt|National Center for Atmospheric Research |
| 発行日 | 1977-01-01 |
| 言語 | eng |
| 内容記述 | S-band time delay measurements were collected from the spacecrafts Helios A and B during three solar occultations in 1975/76 within heliocentric distances of about 3 and 215 solar radii in terms of range, Doppler frequency shift, and electron content. A description is given concerning some characteristic features of the methods of measurement and data processing. Typical data sets are discussed to probe the electron density distribution near the sun (west and east limb as well) including the outer and extended corona. Steady-state and dynamical aspects of the solar corona are presented and compared with earth-bound K-coronagraph measurements. Using a weighted least squares estimation 3 parameters of an average coronal electron density profile are derived in a preliminary analysis to yield electron densities of about 130 billion; 100 million; 7 million/cu m at r?3; 65; 215 solar radii. Transient phenomena are discussed and a velocity of propagation v approximately 900 km/s for plasma ejecta from a solar flare is determined from an extraordinary set of Helios B electron content measurements on April 30/May 1, 1976. |
| NASA分類 | SOLAR PHYSICS |
| レポートNO | 78A10335 |
| 権利 | Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/435110 |
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