Definitive diagnostic ionospheric structure measurements require a synthesis of (1) the theory of propagation in structured media, (2) stochastic processes, and (3) the plasma physics of dynamic structure evolution in the ionosphere. The theory of scintillation was reviewed in Phase Screen Models Revisited Practical applications of the theory followed from the forward propagation equation (FPE). Strict applications of the FPE were constrained by the angular extent of a superposition of plane waves that represented the field. However, in Thoughts on the Phase-Screen Model we argued that near-line-of-sight propagation in a stochastic medium was not subject to the narrow-propagation-angle constraint. In effect, complex scintillation realizations generated using the multiple-phase-screen (MPS) method was more accurate that results derived from the statistical theory of scintillation or the phase-screen theoretical results.
This allowed us to revisit simulations an our interpreting low-latitude measurements of GPS and GNSS scintillation. The updated interpretation is summarized in Extreme Equatorial Structure Variation, which is a poster for presentation at the 2026 AGU meeting in San Francisco Dec 7-11.