VHF Radar for Discovery in the Solar Corona and Geospace
Abstract
In deep space, radar is well known for its application to planetary surfaces and dynamics. The use of radar to study the solar wind, zodiacal light, and the solar corona has also been explored. During the 1960s a dedicated solar radar facility was built and operated for nine years at El Campo, Texas, and several publications suggest that radar is a viable and interesting technique for the study of the sun (e.g. James, Astrophys. J., 146, 356-366, 1966). However, very few other solar observations were available during past observations (H alpha and sunspot counts); radio technology was limited; information has been lost; and recent work has raised new questions about the El Campo, and other, results. Modern technology and techniques have now overcome many of those limitations, and excellent receiving systems now exist, specifically the LOFAR and LWA systems, which can provide high resolution radio imaging of solar radar backscatter, and many new solar instruments are available, providing greatly enhanced possibilities for understanding and interpreting solar radar observations. What is missing is a transmitter powerful enough to match or exceed the specifications of El Campo, and some possibilities will be discussed. Optimal solar radar frequencies are in the 40 to 50 MHz range, and scatter from the coronal plasma would occur at or near the corresponding plasma resonance level, roughly between one and five solar radii from the center of the sun. Because of this, solar radar has the potential to be a productive technique for the study of coronal structure and dynamics, including wave activity, turbulence, and explosive events such as CMEs. A new solar radar transmitter would have many other uses, not only in the solar corona and solar wind, but also in the earth's ionosphere, where radar offers direct measurements of plasma structure, irregularities, and instabilities. A new radio facility in Puerto Rico, the Aguadilla Radio Array, which can be used as a test bed for solar radar observations, will be briefly described.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMSA11C3235I
- Keywords:
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- 7924 Forecasting;
- SPACE WEATHER;
- 7949 Ionospheric storms;
- SPACE WEATHER;
- 7969 Satellite drag;
- SPACE WEATHER;
- 7984 Space radiation environment;
- SPACE WEATHER