The 33rd URSI GASS has been postponed until 2021. See the website for more details.
XXXIII General Assembly and Scientific Symposium (GASS) of the International Union of Radio Science (Union Radio Scientifique Internationale-URSI). The GASS of URSI are held at intervals of three years to review current research trends, present new discoveries and make plans for the future research and special projects in all areas of radio science.
Full details are on the URSI GASS website.