Document Type
Article
Publication Date
7-15-2024
Abstract
Evaporation ducts (EDs) are an atmospheric phenomenon that can cause anomalies in X-band radar systems (8–12 GHz) by extending their range beyond the geometric horizon, potentially leading to positioning uncertainties. Additionally, the lateral spatial variations of the ED over ~60 km may cause further effects. However, the extent to which these lateral variations need to be incorporated for accurate propagation predictions, and whether such effects need to be accounted for in related applications such as refractivity inversion techniques, remains unclear. In addition, few studies have discussed the impacts of heterogeneous EDs on X-band propagation loss relative to a homogeneous ED. To address these questions, this article explores the impact of linear variations of ED height and duct shape over range on X-band propagation loss relative to a laterally homogeneous ED. It is found that significant differences in X-band propagation are likely to occur when horizontal variations of ED height or shape transition the environment’s trapping conditions downrange of the radar transmitter. Furthermore, it is shown that during such transitional trapping environments, heterogeneous refractivity inversions perform more accurately, on average, than homogeneous refractivity inversions. However, utilizing heterogeneous inversion methods when the true environment is homogeneous can lead to less accurate inversely determined refractivity.
This article was published Open Access through the CCU Libraries Open Access Publishing Fund. The article was first published in IEEE Transactions on Antennas and Propagation: https://doi.org/10.1109/TAP.2025.3610041
Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Recommended Citation
D. P. Greenway, D. M. Pastore, A. E. Vaughan and E. E. Hackett, "X-Band Propagation in Laterally Heterogeneous Evaporation Ducts and Its Implications for Refractivity Inversions," in IEEE Transactions on Antennas and Propagation, vol. 73, no. 12, pp. 10634-10649, Dec. 2025, doi: 10.1109/TAP.2025.3610041. Available at https://digitalcommons.coastal.edu/marinescience/10/