Title: A parametric approach to unmixing remote sensing crop growth signatures
Authors: Zhengyuan Zhu - Iowa State University (United States) [presenting]
Colin Lewis-Beck - Iowa State University (United States)
Anirban Mondal - Case Western Reserve University (United States)
Joon Jin Song - Baylor University (United States)
Jonathan Hobbs - Jet Propulsion Laboratory (United States)
Abstract: Remote sensing data is often measured or reported over wide spatial footprints with heterogeneous ground cover. Different types of vegetation, however, have unique signatures that evolve throughout the growing season. Without additional information, signals corresponding to individual vegetation types are unidentifiable from satellite measurements. We propose a parametric mixture model to describe satellite data monitoring crop development in the US Corn Belt. The ground cover of each satellite footprint is primarily a mixture of corn and soybean. Using auxiliary data from multiple sources, we model the aggregate satellite signal, and identify the signatures of individual crop types, using nonlinear parametric curves. Estimation is performed using a Bayesian approach, and information from auxiliary data is incorporated into the prior distributions to identify distinct crop types. We demonstrate our parametric unmixing approach using data from the European Space Agency's Soil Moisture and Ocean Salinity satellite. Lastly, we compare our model estimates for the timing of key crop phenological stages to USDA ground-based estimates.