A Climatology-Based Model for Long-Term Prediction of Radar Beam Refraction

This model uses iterative raytracing to determine the most direct path from the radar to the target through the climatologically predicted refractive atmosphere. The amount of height measurement error is calculated by comparing the geographic path to the refracted path. Only vertical refractivity variation is taken into account, and the effects of ducting and exponential refractivity are both modeled.As a test, the model computed height error at 17 locations worldwide for a target at 10,000 feet and 60 nautical miles.