Characterization of Vegetation and Soil Scattering Mechanisms across Different Biomes using P-band SAR Polarimetry

TL;DR

This study analyzes P-band SAR data across nine North American biomes to separate and characterize soil and vegetation scattering mechanisms using a hybrid decomposition method, enhancing understanding of biophysical surface properties.

Contribution

Introduces a hybrid three-component decomposition approach that does not assume vegetation structure, applied across diverse biomes to distinguish scattering contributions.

Findings

Decomposition effectively separates surface, double-bounce, and vegetation scattering.

Vegetation seasonality significantly affects scattering contributions.

Soil surface roughness influences the scattering mechanisms across biomes.

Abstract

Understanding the scattering mechanisms from the ground surface in the presence of different vegetation densities is necessary for the interpretation of P-band Synthetic Aperture Radar (SAR) observations and for the design of geophysical retrieval algorithms. In this study, a quantitative analysis of vegetation and soil scattering mechanisms estimated from the observations of an airborne P-band SAR instrument across nine different biomes in North America is presented. The goal is to apply a hybrid (model- and eigen- based) three component decomposition approach to separate the contributions of surface, double-bounce and vegetation volume scattering across a wide range of biome conditions. The decomposition makes no prior assumptions about vegetation structure. We characterize the dynamics of the decomposition across different North American biomes and assess their characteristic range. Impacts of vegetation cover seasonality and soil surface roughness on the contributions of each scattering mechanism are also investigated. Observations used here are part of the NASA Airborne Microwave Observatory of Subcanopy and Subsurface (AirMOSS) mission and data have been collected between 2013 and 2015.