The investigators will develop a prototype of next generation meteor radars with improved ability for deriving neutral winds, temperatures and individual meteor properties. The data will be used to determine a more accurate characterization of the global meteor flux and its effect on upper atmospheric physics. The radar will be operated at a site in Pennsylvania and will be capable of observing at least two of three primary types of meteor reflection: 1) the commonly used specular meteor trails; 2) the recently understood non-specular trails, which result from plasma instability and turbulence generated field aligned irregularities (FAI); and 3) meteor head-echoes, which are a radar target moving at the speed of the meteoroid. Since the system can detect and resolve in time and space at least two mechanisms, we can study the observation biases introduced by each technique. These biases plague our current characterization of the meteor input function into the upper atmosphere, introducing uncertainties in the estimates of atmospheric parameters. Additionally, the detailed radio signature produced by both head echoes and non-specular trails are far more complex than specular echoes. The system will be designed using the latest digital technology, improving the available data for the study of both meteors, and the dynamics and energetics of themesosphere and lower thermosphere (MLT) atmospheric region. The investigators have built strong domestic and international collaborations that will be crucial in achieving the scientific and educational goals of the program. The research will provide undergraduate and graduate students exposure to a wide variety of fields including aeronomy, meteor science, design and construction of radar systems, radio frequency engineering, and software radar.
The research activity under this grant has been directed towards the design, implementation, and operation of a new prototype of the next generation of meteor radars to study the Upper regions of the Earth’s atmosphere. This new type of radar is enabling new space science research in Penn State and elsewhere by linking our new digital hardware and radar processing techniques with other research facilities in the United States and overseas. The radar is portable and can be deployed to support NASA rocket campaigns to study the ionosphere or collocated next to other NSF research facilities to pursue scientific discoveries. The new meteor radar has been successfully implemented and is fully operational near Penn State main campus. We have demonstrated that this type of medium powered radar is able to detect head-echoes, specular, and non-specular echoes. Since the radar is oriented perpendicular to the Earth’s magnetic field, it is sensitive enough to capture plasma instabilities that develop in the ionosphere. These types of plasma instabilities can cause disruption to satellite communications, GPS navigation systems, and in general to any space device that orbits the Earth. If sufficient funding is available, we could study these plasma irregularities in more detail. We have presented results from our radar meteor modeling at national and international scientific meetings. The next step—given sufficient funding—is to continue our meteor modeling and better assess the meteor flux in the Earth’s atmosphere. An excellent addition to this research would be to collate four additional antennas and receivers systems to allow experimentation with imaging and emerging signal-processing techniques such as compressive and cognitive sensing. All instrumentation developed under this effort is available for community use under a collaborative agreement. This grant supported many undergraduate and graduate students. In particular, six MS theses, two PhD theses as well as six journal papers along with more than ten posters given at the 2013 CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions) Workshop, six international conference papers, and more than ten national conference papers.
