An Assessment of SAOCOM <italic>L</italic>-Band PolInSAR Capabilities for Canopy Height Estimation: A Case Study Over Managed Forests in Argentina

Abstract

This work presents the first results of canopy height mapping with L-Band SAOCOM data by means of Polarimetric SAR Interferometry (PolInSAR). For this study case, a colocated temporal series of SAOCOM fully polarimetric images covering the year 2021 was acquired, with a temporal baseline of 8 to 16 days between each acquisition. The study area corresponds to managed forests in Corrientes, Argentina, one of the main forest production regions in the country. Field measurements provided by forest owners were available in order to validate the obtained results, along with canopy height measurements from the Global Ecosystem Dynamics Investigation mission. A multi-baseline PolInSAR approach was adopted, following the methodology proposed by previous works. The results show that this multi-baseline selection approach is more appropriate than a single-baseline one, given the high variability that SAOCOM presents in the spatial baseline between acquisitions, and the lack of orbital control over this parameter. The height maps obtained over a validation site yielded an average $R^{2}$ of 0.72 and a mean $RMSE$ of 2.35 m., in agreement with the figures obtained in similar studies. This study presents, for the first time, canopy height maps of 8 and 16-day temporal baselines, L-band, orbital interferograms. The conclusions yielded by this research represent a qualitative and quantitative evaluation of SAOCOM PolInSAR capabilities for forest height mapping. It is also relevant to assess the suitability of the RVoG model to characterize the structure of these forests with L-band data retrieved by the Argentinean constellation.

Keywords

• Forest height
• InSAR coherence
• Satélite Argentino de Observación con Microondas (SAOCOM-1)