Tropospheric effects of time delays and angle of arrivals in the low elevation angle for radiowave propagation

Effects of tropospheric radiowave propagation were studied based on ray-tracing and parametric approach with empirical data, ECM (European Climatological Medium-range) data, supplied by the National Climatology Data Center in Asheville, North Carolina. Results indicate that time delays and angle of arrival errors vary dynamically in seasons, months, and regions. The error in both time delay and angle of arrival are higher than expected, and should not be neglected for higher accuracy requirements in elevation angles of less than 10/spl deg/.