In order to properly understand the complex interactions of charged particles in the earth's magnetosphere, it is important to study the dynamics and configuration of the high-latitude polar region which is composed of the auroral zone and polar cap. This grant focuses on studies of the polar magnetospheric using low-altitude observations of precipitating particles and satellite auroral imagery. Specifically, studies of the low- altitude cusp and signatures of the mantle will be undertaken in order to answer questions of how low-altitude ionospheric processes can be used to remote sense distant magnetospheric phenomena. This study is important to the Geospace Environment Modelling Program at NSF.