In GNSS-denied (or contested) environments, platform navigation performance is dominated by the accuracy of onboard inertial sensors. Even with high-end inertial sensors, which exhibit extremely low bias and drift, it is not possible to avoid the build up of navigation errors over long-time frames (Titterton & Weston, 2004). Removing these accumulated navigation errors is crucial to retain the confidence of navigation accuracy (Groves, 2013). This removal, or correction, is achieved using one or more aiding sources that provide positional information, i.e., a position fix. Aiding sources can be categorized into three groups based on the technologies involved: 1) Radio-based aiding, which uses a transmitted ratio signal to obtain