Dear all. This email is to advertise you about a session planned for the next URSI Asia-Pacific Radio Science Conference (AP-RASC 2025https://ap-rasc.com/home.php, Sydney, Australia, 17-22 August 2025) about the exploitation of RO data for Ionospheric Monitoring and Space Weather. The session (see here below a brief description) is organized within the URSI Commission G (Ionospheric Radio and Propagation)https://ursi.org/files/G/TOR.htm activities. All the information about paper submission (deadline, February, 20th 2025) can be found herehttps://ap-rasc.com/papersubmission.php. Session G01: GNSS Radio Occultation and zenith data from Low Earth Orbit: advancements on measurements, data assimilation and models Description: Nowadays several CGMS (Coordination Group for Meteorological Satellites) coordinated and commercial Low Earth Orbiting (LEO) satellites host Global Navigation Satellite System (GNSS) receivers. Topside and radio occultation measurements are becoming fundamental to map the 4D distribution of the free electrons in the Earth atmosphere. The assimilation of such GNSS dual frequency measurements into numerical models has in fact the potential to contribute significantly to the improvement of the ionosphere and plasmasphere monitoring, forecasting and modelling, with important benefits for a better understanding of the space weather. Moreover, techniques for measuring and mapping turbulence strength from small-scale irregularities are also emerging. In this session the contributions on new techniques to estimate the electron density and electron content distribution and irregularities from GNSS LEO topside and radio occultation data, their ingestion into data assimilation models and corresponding applications (e.g. detection of Space Weather, earthquake and tsunami signatures, support to precise navigation), are welcome. Best regards, Riccardo Notarpietro, Remote Sensing Scientist - Radio Occultation Any email message from EUMETSAT is sent in good faith but shall neither be binding nor construed as constituting a commitment by EUMETSAT, except where provided for in a written agreement or contract or if explicitly stated in the email. Please note that any views or opinions presented in this email are solely those of the sender and do not necessarily represent those of EUMETSAT. This message and any attachments are intended for the sole use of the addressee(s) and may contain confidential and privileged information. Any unauthorised use, disclosure, dissemination or distribution (in whole or in part) of its contents is not permitted. If you received this message in error, please notify the sender and delete it from your system.