Evaluation of multi-orbital SAR and multi-sensor optical data for empirical estimation of rapeseed biophysical parameters

Aubin Allies, Antoine Roumiguie, Jean-Francois Dejoux, Remy Fieuzal, Anne Jacquin, Amanda Veloso, Luc Champolivier, Frederic Baup
2021 IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing  
This paper aims to evaluate the potential of multitemporal and multi-orbital remote sensing data acquired both in the microwave and optical domain to derive rapeseed biophysical parameters (crop height, dry mass, fresh mass and plant water content). Dense temporal series of 98 Landsat-8 and Sentinel-2 images were used to derive Normalized Difference Vegetation Index (NDVI), green fraction cover (fCover) and Green Area Index (GAI), while backscattering coefficients and radar vegetation index
more » ... ) were obtained from 231 mages acquired by Synthetic Aperture Radar (SAR) onboard Sentinel-1 platform. Temporal signatures of these Remote Sensing Indicators (RSI) were physically interpreted, compared each other and to ground measurements of biophysical parameters acquired over 14 winter rapeseed fields throughout the 2017-2018 crop season. We introduced new indicators based on the cumulative sum of each RSI that showed a significant improvement of their predictive power. Results particularly reveal the complementarity of SAR and optical data for rapeseed crop monitoring throughout its phenological cycle. They highlight the potential of the newly introduced indicator based on: the VH polarized backscatter coefficient to estimate height (R 2 = 0.87), plant water content (R 2 = 0.77, from flowering to harvest) and fresh mass (R 2 = 0.73) and RVI to estimate dry mass (R 2 = 0.82). Results also demonstrate that multi-orbital SAR data can be merged without significantly degrading the performance of SAR-based relationships, while strongly increasing the temporal sampling of the monitoring. These results are
doi:10.1109/jstars.2021.3095537 fatcat:up2kmyxwgbajdh4w3ao7evk63i