Inland water 3D monitoring: GEDI and SWOT missions potential and challenges

Inland surface water is the most accessible water resource, of fundamental importance in several respects, at first freshwater supply for people and other living beings, agriculture and natural environment, industry and other human activities.

Its availability is threatened by climate change and its continuous monitoring worldwide is becoming of higher and higher relevance, being directly connected to the main goals of two UN SDGs, 6 (Clean water and sanitation) and 13 (Climate action).

It is therefore not surprising that a growing attention is reserved to the inland surface water monitoring through remote sensing sensors and methods, being this monitoring focused on the variation of the volume of the available water resources and not only on their extension, as already successfully done in the past at least from the launch of the Landsat missions in 1972: a 3D instead a 2D monitoring is nowadays in the spotlight.

To this aim, the Surface Water and Ocean Topography (SWOT) mission, whose spacecraft was placed in the final orbit in July 2023, and the Global Ecosystem Dynamics Investigation (GEDI) mission, reactivated onboard the International Space Station in December 2024, will play a key role.

Here methodologies are proposed to routinely process GEDI and SWOT data, based on thorough investigations on GEDI data collected in the period 2019-2023 and a preliminary investigation on SWOT data collected in 2024, highlighting the problems and potentials of these data and the open challenges to face with in the coming future.