Modeling of Ionospheric Refraction of UHF Radar Signals at High Latitudes

A three-dimensional ray-tracing code has been developed to run in conjunction with the University of Alaska polar ionospheric model. The ionospheric model may be run in a real-time predictive mode and its outputs have been used as an input to the ray tracing code. The objective of this work is to compute refractive effects on UHF radar signals due to time-varying ionospheric structures at high latitudes. Radar range and pointing errors are calculated continuously during two 24-hour periods in this paper to demonstrate the effects from a time-varying ionosphere during quiet and moderately disturbed geomagnetic conditions. Radar pointing errors that correspond to target errors up to about 500m have been found for low antenna elevation radar pointing directions during moderately disturbed geomagnetic conditions. See also ADM002065. Presented at the Specialist's Meeting of the Information Systems Technology (IST) Panel entitled Characterising the Ionosphere, held in Fairbanks, Alaska, on 12-16 Jun 2006. Published in the proceedings of the meeting, RTO-MP-IST-056, p19-1 through 19-14, 2006. The original document contains color images.