The objective of this research is to develop channel models for radio wave propagation with antennas installed very near ground (H+), at ground level (H0), and/or covered by ice, water, snow, or other materials (H-). The approach is to evaluate the temporal, spatial and spectral statistical characteristics of very near ground antenna channels through simulations, analysis, and measurements conducted in an anechoic chamber and in real environments.
Intellectual Merit: The conducted research includes: 1) development of physics-based propagation models for H+/H0/H- radio channels over a wide range of frequencies to address a variety of applications; 2) exploration of the effect of transmitter and receiver antenna heights, frequency, bandwidth, rough surface materials, and the degree of roughness on the channel model; 3) investigation of near-ground channel dispersion and its impact on direction-of-arrival and time-of-arrival estimation; 4) study of the effect of ground roughness and bandwidth on amplitude, phase, and time-of-arrival statistics in both line-of-sight and non-line-of-sight scenarios as well as spatial correlation and its effect on multi-input-multi-output systems; and 5) design of proper antenna elements and antenna arrays for H+/H0/H- situations.
Broader Impacts: This research should enable optimal design of wireless sensor networks and localization systems for applications such as autonomous collision avoidance, multi-robot collaboration, safety services (firefighting), and under-ground exploration, which would benefit the national economy and security. This project integrates research with education and outreach activities. The theoretical work is demonstrated by practical applications through laboratory activities and measurement processes. Hands-on experiences will be provided for undergraduate students and school teachers. Underrepresented minority students will be recruited into engineering education.