SMOS radiometric data is used to derive Faraday rotation for a number of orbits combining several scenarios: land, ice and water. Results compare very well with the values theoretically predicted from available ionosphere and geomagnetic field data.
Wu, L. [et al.]. Faraday rotation angle retrieval using SMOS radiometric data. A: Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment. "13th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment: MicroRad 2014: proceedings: 24-27 March 2014: Pasadena, California, USA". Pasadena: Institute of Electrical and Electronics Engineers (IEEE), 2014, p. 139-140.