NSSDCA ID: 1968-100A-03
Mission Name: Pioneer 9Both 423.3-MHz and its 2/17 subharmonic 49.8-MHz signals were transmitted from a 4.6-m steerable parabolic antenna at Stanford University to the two-frequency radio receiver on the spacecraft. The high-frequency signal served as a reference signal, since its propagation time was not appreciably delayed. The low-frequency signal was delayed in proportion to the total electron content in the propagation path. On the spacecraft, a phase-locked receiver counted the beat frequency zero crossings of the received signals to obtain measurements of phase-path differences. Differential delay of the group velocity was also observed, and these values were telemetered to the ground station and used to calculate the total electron content. The ionospheric contribution (up to a selected altitude obtained from other experimental techniques) could be subtracted to produce data describing the interplanetary electron content of the solar wind and its variations. More detailed descriptions of the experiment can be found in J. Geophys. Res., v. 71, pp. 3325-3327, and in Radio Sci., v. 6, pp. 55-63.
Questions and comments about this experiment can be directed to: Coordinated Request and User Support Office
Name | Role | Original Affiliation | |
---|---|---|---|
Dr. Thomas A. Croft | Other Investigator | SRI International | tomcroft@kl.sri.com |
Mr. Ray L. Leadabrand | Other Investigator | SRI International | |
Dr. A. M. Peterson | Other Investigator | Stanford University | |
Prof. H. Taylor Howard | Other Investigator | Stanford University | |
Mr. R. A. Long | Other Investigator | SRI International | |
Prof. Von R. Eshleman | Principal Investigator | Stanford University | eshleman@nova.stanford.edu |