Radio frequency propagation modeling is an integral part of a wide variety of scientific studies and technological applications. Many models and applications consider the effects of ionospheric refraction, magneto-ionic splitting, plasma and neutral collisions, scintillation, traveling ionospheric disturbances, sporadic-E, spread-F, and land-surface interactions. Recent advances in computational power, as well as data collection, storage, and distribution capabilities, have led to an improved ability to include these effects at a higher fidelity, and modern digital signal processing techniques have led to an improved ability to assess the utility of including them. This session seeks contributions covering advancements in measurement, modelling, and prediction techniques pertinent to the interaction of radio waves with the ionosphere in either a skywave or transionospheric propagation mode. Contributions highlighting improvements in our ability to include and understand the Earth’s interactions with these propagation modes are especially encouraged.