Can surface elevation from SWOT over wet land areas be used to generate a DEM?

The Surface Water and Ocean Topography (SWOT) mission, launched at the end of 2022, marked a new area within satellite altimetry. Based on the data collected so far, many new and innovative results have already been obtained, e.g., for inland water,  coastal areas, and the ocean. In addition to reflections from these classical, permanent water sources, SWOT also provides potentially valid surface water elevations from temporary wet areas, such as fields and similar surfaces. In this initial study, we intend to investigate the quality of SWOT surface elevation from these surfaces. Denmark is continuously (in 5-year periods) mapped by airborne lidar campaigns to reconstruct an accurate (5 cm error) high-resolution (40 cm) digital elevation model. This high-quality data set enables investigation of the quality of SWOT observations over wetland areas. In this study, we will apply pixel cloud observations from several scenes to generate a SWOT-based DEM, assuming the surface is stationary, so that variations and noise in the SWOT observations will average out over time. Here, we will investigate the potential for selected areas in Denmark.