Characterization of scattering mechanisms in soil and vegetation for roughness and moisture estimation using active and passive microwave observations

Abstract

The complexity of our Earth system makes the investigation of its critical variables indispensable in order to understand the interrelationships and interactions of different sub-systems and processes in detail. Various parameters play a key role in the global weather and climate system of our Earth, as they control interactions and exchange processes as well as link the water, carbon, and energy cycles worldwide. Accordingly, the global determination and long-term monitoring of important geophysical parameters, such as soil moisture and soil surface roughness, is of significant relevance, especially in terms of, for instance, improving weather and climate forecasts, quantifying net carbon fluxes, and monitoring the condition assessment of existing infrastructures (e.g., roads). In this thesis, active and passive microwave remote sensing is exploited to estimate soil moisture and soil surface roughness. The associated methods developed herein and conducted analyses are of high importance, since the recording of geophysical parameters makes an essential contribution to climate and ecosystem research. It addresses the possibility to close a research and knowledge gap in remote sensing and proposes new approaches in the field of microwave remote sensing for soil- and vegetation-related parameter estimation. High consistencies between retrieval results and auxiliary data (in situ, model and reanalysis) confirm the feasibility of the proposed approaches. The innovation of this study lies specifically in the detailed analysis of longwave microwaves of low frequencies (L- to P-band).