Direction-Finding Measurements of Type III Radio Bursts out of the Ecliptic Plane.

摘要

Direction-finding measurements with the plasma wave experiments on the HAWKEYE 1 and IMP 8 satellites are used to find the source locations of type III solar radio bursts in heliocentric latitude and longitude in a frequency range from 31.1 kHz to 500 kHz. IMP 8 has its spin axis perpendicular to the ecliptic plane; hence, by analyzing the spin modulation of the received signals the location of the type III burst projected into the ecliptic plane can be found. HAWKEYE 1 has its spin axis nearly parallel to the ecliptic plane; hence, the location of the source out of the ecliptic plane may also be determined. Using an empirical model for the emission frequency as a function of radial distance from the sun the three-dimensional trajectory of the type III radio source can be determined from direction-finding measurements at different frequencies. Since the electrons which produce these radio emissions follow the magnetic field lines from the sun these measurements provide information on the three-dimensional structure of the magnetic field in the solar wind.