Radar Characterization of the Interplanetary Meteoroid Environment

We propose a new modeling effort that will make substantial refinements and improvements to our existing models of the interplanetary meteoroid environment near Earth. Because of recent theoretical and observational advancements within the field of radar meteors, we believe that existing models for the interplanetary meteor environment that are based upon or validated with radar meteor observations (Such as the NASA Meteoroid Enviornment Model MEM) lack important theoretically underpinning, and can be improved. Specifically, we now understand that the plasma generated during meteor entry is highly unstable and turbulent, and the evolution of this plasma, is at all stages largely influenced by plasma processes such as wave and ambipolar electric fields. Yet this has not been taken into account in any detailed radar meteor scattering theory. We propose to use our existing and on-going plasma simulations and models to provide the input profiles of conductivity and permittivity for finite difference time domain (FDTD) simulations which can then interrogate the structure using plane waves that replicate radar pulses over the range of used frequencies from HF to L-Band. Using this approach together with our models for how the meteor plasma varies as a function of both meteor parameters such as size, composition, and velocity, and, atmospheric parameters such as winds/electric fields, density, temperature and altitude, will allow us to understand and characterize the full range of radar derivable information from meteors. Achieving these proposed goals will close the existing information gap and resolve the conflicting observations we have on the interplanetary meteor flux. Our results will provide a revised model for the interplanetary meteoroid environment that will strongly support NASA's planned manned and un-manned missions near Earth and to the Moon and Mars.