Meteoroid Plasma Density and Mass Determination Using a New Spherical Scattering Method Applied to Head Echoes
Abstract
Large-aperture radars have the ability to detect the high-density plasma that forms around a meteoroid, measuring reflections called head echoes. To determine the head echo plasma density, we have modeled the scattering of a radar wave by meteor-generated plasma. This allows us to use head echo measurements to infer plasma density and, subsequently, meteoroid mass with unprecedented accuracy. To validate our new scattering method, we first used the spherical scattering model to compare densities derived from simultaneous VHF and UHF measurements of individual head echoes. We then converted the maximum plasma density from these head echoes to meteoroid masses by using an ionization model and compared these values with those obtained from a meteoroid ablation model. These tests indicate that our scattering method produces consistent results across frequencies that agree remarkably well with the ablation model for most meteor measurements. The data presented in this research derives from a set of measurements collected by ALTAIR at both VHF and UHF during the Leonid 1998 and 1999 showers. This new technique allows meteor researchers to use highly sensitive, large-aperture radars to map meteoroid masses and origins for particle masses down to 10-8 grams.
- Publication:
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AGU Spring Meeting Abstracts
- Pub Date:
- May 2004
- Bibcode:
- 2004AGUSM.P33C..07C
- Keywords:
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- 6205 Asteroids and meteoroids;
- 6929 Ionospheric physics (2409);
- 6952 Radar atmospheric physics;
- 6964 Radio wave propagation