GNSS-R Parameter Sensitivities for Soil Moisture Retrieval

We consider the problem of retrieving soil moisture based on GNSS-R time series data with incidence angle diversity in the presence of instrument calibration errors, vegetation cover uncertainty, and surface roughness uncertainty. After defining an observation model and a retrieval cost function, we derive a formula for retrieval performance as a function of calibration uncertainty, time series parameters, and prior statistics. Numerical results illustrate relationships among various parameters.