A PHYSICALLY-BASED MULTI-TIMESCALE MODELLING FRAMEWORK OF DYNAMIC VEGETATION SIGNALS FOR SAR - EXPRO PLUS

The objective of this activity is to develop a physically-based framework that describes and simulates the temporal variation and fluctuations of the scattered SAR signal induced by vegetation. To achieve this, the Contractor shall define such framework and its architecture, along with the necessary interfaces, the different components, and the expected inputs and outputs, focusing on representing the scattering of SAR signals by vegetated land surfaces. The framework shall be modular and applicable to a wide range of present and future missions and scenarios, and shall allow the use and intercomparison of different modelling approaches. It shall be designed to:1. cover multiple frequencies of the incident signal, with a focus on C-band and L-band as a minimum2. accommodate the simulations of the effects of several categories of vegetation, e.g. from forests to agricultural fields3. capture different temporal scales of the signal evolution in the simulations, that could range for example from seconds to days4. Output the complex scattered field, which can then be used for subsequent performance analysisFurther, the Contractor shall develop the models that go into the framework and validate them using existing spaceborne, airborne and on-ground datasetswhen available. The models shall be physically-based, describe the scattering mechanisms with sufficient accuracy, and shall be parameterized and validated using experimental observations. The validation shall be focused on a limited number of scenarios, that must be representative of candidate SAR missions (like Hydroterra+) and planned SAR missions (e.g. ROSE-L). After implementation and validation, the Contractor shall analyse the outputs of the simulations and conduct sensitivity analyses, to understand and characterize the impact of vegetation on both amplitude and phase of the output observations, and its effect on the Single Look Complex (SLC) and interferometric products.