Within the framework of Earth Observation (EO), microwave remote sensing is a mature technology boosting a seamless monitoring and mapping of Earth’s resources and human activities at various spatial and temporal scales. With respect to other competing EO technologies, microwave remote sensing systems offer imaging performance insensitive to daylight and weather conditions. This special session addresses the latest advances in theoretical and experimental aspects of information retrieval using either active (e.g., synthetic aperture radar, scatterometers, altimeters) or passive (e.g., Global Navigation Satellite System-Reflectometry, radiometers) remote sensing technologies, with a special focus on: new direct and inverse models for EO data; models, methods, simulation, and measurements for electromagnetic scattering at microwaves; statistical modeling; multi-dimensional (multi-sensor, multi-modal, multi-frequency, multi-polarization, multi-resolution, multi-temporal) EO data processing; information retrieval using physical-based machine and deep learning methods.