Analysis of Perseid meteor head echo data collected using the advanced research projects agency long-range tracking and instrumentation radar (ALTAIR)

The 1998 Perseid meteor shower was observed using the Advanced Research Projects Agency (ARPA) Long-Range Tracking and Instrumentation Radar (ALTAIR) in order to study potential meteoroid impact on orbiting spacecraft. ALTAIR is a dual-frequency radar that operates at VHF and UHF, and its high sensitivity and precise calibration make it uniquely suited for detecting meteor head echoes. ALTAIR is dually polarized and records left-circularly and right-circularly polarized signal returns, which allow the determination of polarization ratios. ALTAIR uses a multihorn feed and interferometry to measure target angle of arrival. This paper contains analysis on Perseid data that were collected at VHF (158 MHz). Meteor head echo statistics are presented, including mean altitude, radial velocity, radar cross section (RCS), and polarization ratio. ALTAIR's VHF detection rate was approximately 1 head echo per second. An in-depth analysis on select head echoes to estimate meteor decelerations and densities has also been included.