Validation of the Global Assimilation of Ionospheric Measurements (GAIM) Model

The Utah State University (USU) Global Assimilation of Ionospheric Measurements (GAIM) model version 2.3 uses the Ionosphere Forecast Model (IFM), a physics-based model, and a Kalman filter using Gauss-Markov relaxation as a basis for assimilating a set of real-time measurements to produce a specification and forecast of the ionosphere. This model is currently being transitioned at the Air Force Weather Agency (AFWA) for operational use. As part of that process, the Air Force Research Laboratory (AFRL) has been performing a validation of GAIM. The primary focus of the work has been to determine if an operational GAIM will perform better than the current operational ionospheric model (the Parameterized Real-Time Ionospheric Specification Model, PRISM). In this presentation, we will discuss our results that illustrate that GAIM is generally superior to both climatology (IFM) and PRISM. We will also discuss data preprocessing, the robustness of GAIM, and some of the validation questions that remain unanswered.