Measuring solar wind velocity with spacecraft phase scintillations
Abstract
THE discovery of interplanetary scintillations (IPS) of natural radio sources1 has been followed by extensive multiple-station or spaced-receiver IPS measurements of the solar wind velocity in regions not yet probed by direct spacecraft2-8. Few measurements have, however, been obtained within 40 Rsolar because amplitude or intensity scintillations saturate when they are strong as is the case near the Sun. This is unfortunate because the scarcity of wind velocity measurements in the acceleration region close to the Sun is one of the reasons why the construction of a unique picture of solar wind dynamics has not yet been possible, despite numerous theoretical studies and direct spacecraft observations farther out9,10. The demonstration of the measurement of spacecraft phase scintillations with a coherent dual-frequency radio system11 paves the way for making solar wind velocity measurements with multiple-station phase scintillations. Although similar in principle to the IPS technique, several factors make this new tool a more powerful and promising one.
- Publication:
-
Nature
- Pub Date:
- April 1977
- DOI:
- 10.1038/266514a0
- Bibcode:
- 1977Natur.266..514W
- Keywords:
-
- Phase Deviation;
- Radio Sources (Astronomy);
- Scintillation;
- Solar Wind Velocity;
- Amplitudes;
- Interplanetary Medium;
- Signal To Noise Ratios;
- Solar Physics