Monitoring the terrestrial water cycle—including soil moisture, surface water, floods, drought, groundwater depletion, and hydrologically driven land deformation—requires observations across multiple spatial and temporal scales that no single satellite technique can fully capture. This short course addresses this challenge by bringing together four spaceborne approaches—GNSS-R, GRACE/GRACE-FO, InSAR/SAR, and P-band Signals of Opportunity (SoOp)—that offer complementary perspectives on hydrological processes, leveraging each technique's distinct physical sensitivities, sensing depths, and spatio-temporal trade-offs.

Rather than presenting these as four separate topics, the course emphasizes their synergy: how GNSS-R's frequent, sub-daily surface soil moisture retrievals complement SAR's finer spatial resolution and SoOp's sensitivity to root-zone moisture; how InSAR's high-resolution deformation measurements relate to GRACE/GRACE-FO's large-scale water-storage signals; and how SAR/InSAR observations can provide additional information on snow and glacier dynamics in cryospheric headwater regions.

Through short technique-focused talks, hands-on browser-based demonstrations of open data portals and processing tools, and a closing discussion, participants will see how combining these observations can offer a more comprehensive understanding of hydrological and cryospheric processes than any single technique alone.

The course is relevant to Geodesy (G), Hydrological Sciences (HS), Earth and Space Science Informatics (ESSI), and Natural Hazards (NH), with connections to Cryospheric Sciences (CR). It is designed to foster cross-disciplinary dialogue and collaboration between geodesists, remote sensing scientists, hydrologists, cryospheric scientists, and data scientists.