L. Liu and Y. J. Morton. Assessment of storm-time ionospheric electron density measurements from Spire Global CubeSat GNSS radio occultation constellation. GPS Solutions, volume 27, issue 2, 2023 . B. Park, C. Lim, J. Wang, and Y. T. J. Morton. Horizontal Drift Velocity and Dimensions of Ionospheric Irregularities Using ROT From a GNSS Receiver Array. IEEE Transactions on Geoscience and Remote Sensing, volume 60, 2022 .