Accession Number : ADA113083

Title :   STIP VII: Four Neighboring Radio Paths Traverse the Northern Corona in 1979.

Descriptive Note : Final rept. May 79-Sep 81,

Corporate Author : SRI INTERNATIONAL MENLO PARK CA

Personal Author(s) : Croft,Thomas A

PDF Url : ADA113083

Report Date : Dec 1981

Pagination or Media Count : 80

Abstract : In August and September, 1979, a unique parade of spacecraft could be observed. With reference to the ecliptic plane, Pioneer Saturn, Voyager 1 and Voyager 2 appeared to move from left to right, about one degree north of the sun, while Pioneer Venus traversed the same path from right to left. Because the influence of the sun on radio signals is concentrated in the region nearest the sun, we are able to use the radio signals from these four spacecraft as probes of the solar corona. The spacecraft parade offered two types of opportunities that are closely related: first, those due to the multiple observations in the same region of the corona, and second, the three opportunities when pairs among the four spacecraft passed close to one another in the sky. Because Pioneer Venus traveled eastward relative to the sun while the others traveled westward, it follows that Pioneer Venus made a close approach to each of the other three. The value of data emerging from these interplanetary recording sessions is enhanced because the events occur in the midst of STIP Interval VII during which the northern and equatorial corona were monitored by many diverse techniques. The gathering of four spacecraft behind the northern corona serves as a means for tracking the macroscopic flow patterns in the corona and relating the patterns to scintillations white-light coronagraphs, high-energy particle distributions, radio noise bursts, spectroheliograms, magnetograms, radio-star scintillations, and the like.

Descriptors :   *SOLAR CORONA, *RADIO INTERFERENCE, *SCINTILLATION, RADIO TRANSMISSION, RADIO SIGNALS, RADIO BEAMS, SPACECRAFT, INTERPLANETARY SPACE, INTERACTIONS

Subject Categories : Astrophysics
      Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE