Nowadays, the refracted, reflected and scattered signals of global navigation satellite systems (GNSS) have been widely used to remotely sense the Earth's atmosphere, ocean and land. Also an integrated approach of synthesizing various remote sensing data and combining them with in situ measurements and geophysical models is highly desirable. This session will address current remote sensing capabilities, progress and future directions for atmospheric sounding, soil moisture, water cycle, glacier melting, ocean circulation, and geohazard monitoring using GNSS-Reflectometry, GNSS Radio Occultation and other sensors. This session also welcomes submissions that combine GNSS with in-situ observations, SAR, Scatterometry and Altimetry data for monitoring, comparing and calibration, as well as propose new applications for these observations, and present future missions/challenges. Papers on emerging technologies and combination of existing and new sensors including those deployed on aircraft and on operational applications are particularly encouraged.