The Helios Faraday Rotation Data Archive

The Helios Faraday Rotation (FR) Experiment, a passive radio science investigation requiring no on‐board hardware other than the existing spacecraft radio subsystem, was designed to study the dynamic and quiescent structure of the magnetic fields and electron density in the solar corona. Measurements of coronal Faraday rotation were derived from the linearly polarized S‐band downlink carrier signal, which probed otherwise inaccessible regions of the corona in the radial range from 2 to 15 solar radii during the regularly recurring solar conjunctions. More than 1250 hours of Helios FR data were recorded over the duration of the Helios 1 (1974–84) and Helios 2 (1976–80) missions. The time scales of FR variations provide information on various physical phenomena: (a) slowly‐varying rise and fall associated with the changing ray path offset, combined with the rotation of the quasi‐static corona; (b) ubiquitous random oscillations with higher fluctuation amplitude at smaller solar offset distances, probably ca...

[1]  M. Bird,et al.  Quasi-harmonic faraday-rotation fluctuations of radio waves when sounding the outer solar corona , 2000 .

[2]  M. Pätzold,et al.  The Pioneer 6 Faraday rotation transients‐On the interpretation of coronal Faraday rotation data , 1998 .

[3]  M. Bird,et al.  Characteristics of Coronal Alfvén Waves Deduced from Helios Faraday Rotation Measurements , 1997 .

[4]  A. Efimov,et al.  Intensity of coronal Alfvén waves from polarization radio sounding , 1997 .

[5]  R. Woo.  Evidence for the reversal of magnetic field polarity in coronal streamers , 1997 .

[6]  M. Bird,et al.  Faraday rotation fluctuation spectra observed during solar occultation of the Helios spacecraft , 1995 .

[7]  H. T. Howard,et al.  Galileo radio science investigations , 1992 .

[8]  H. Volland,et al.  CORONAL ALFVÉN WAVES DETECTED BY RADIO SOUNDING DURING THE SOLAR OCCULTATIONS OF THE HELIOS SPACECRAFT , 1992 .

[9]  H. Volland,et al.  The mean coronal magnetic field determined from HELIOS Faraday rotation measurements , 1987 .

[10]  N. R. Sheeley,et al.  White-light and radio sounding observations of coronal transients , 1985 .

[11]  H. Volland,et al.  Possible evidence for coronal Alfvén waves , 1982 .

[12]  J. Trainor.  The Helios solar probes science summaries , 1980 .

[13]  M. Shea,et al.  Study of Travelling Interplanetary Phenomena 1977 , 1977 .

[14]  H. Volland,et al.  Helios-1 Faraday rotation experiment: results and interpretations of the solar occultations in 1975. , 1977 .

[15]  A. L. Price.  Faraday Rotation Experiment , 1974 .

[16]  W. Rusch,et al.  The quasi-stationary coronal magnetic field and electron density as determined from a Faraday rotation experiment , 1970 .

[17]  W. Rusch,et al.  Pioneer 6: Measurement of Transient Faraday Rotation Phenomena Observed during Solar Occultation , 1969, Science.