Deep learning based retrieval of biomass and forest height using SAR images.

M-GEO
ACQUAL
Staff Involved
M-SE Core knowledge areas
Spatial Information Science (SIS)
Topic description

Aboveground forest biomass has fundamental role in carbon cycling, climate processes, and global warming. Information on the spatial distribution of biomass is a prerequisite for understanding and managing the processes involved in the carbon cycle, and supports international policies for climate change mitigation and adaptation. Several remote sensing techniques were used to map biomass, and yet, biomass cannot be estimated without uncertainty. One of the uncertainties is related to the missing element of the vertical structure of the forest in the remote sensing images. Unlike optical images, the signal from SAR can penetrate the tree canopy and sense the ground beneath the foliage. Therefore, SAR images comprise the information about the structure of the forest and thus are a useful source of information to address the uncertainty in biomass mapping. This proposal aims to apply Deep Learning to SAR images to resolve the uncertainty and estimate biomass in tropical forest regions.

Topic objectives and methodology

The objective is to train a deep convolutional neural network to estimate biomass in forested areas. A set of SAR images from a tropical forest region in French Guiana is available to train and test the network. To make the network sensitive to the vertical structure of the forest, a time series SAR images in interferometric and tomographic acquisition mode with dependence on the vertical component is used as input to the network. In addition, information from the available lidar-based DSM can also be considered for further improvement. Thus, the idea is to use multiple SAR images to train the network and build a model that estimates forest biomass and forest height based on the horizontal and vertical structures of the forest. The initial solution for developing the model can be the multi-channel Monet mapping method proposed in the following paper.

 

References for further reading


Liao, Z., He, B., & Quan, X. (2020). Potential of texture from SAR tomographic images for forest aboveground biomass estimation. International journal of applied earth observation and geoinformation, 88, 102049

S. Vitale, H. Aghababaei, G. Ferraioli, V. Pascazio and G. Schirinzi, "A Multi-Objective Approach for Multi-Channel SAR
Despeckling," 2021 IEEE International Geoscience and Remote Sensing Symposium IGARSS, 2021, pp. 419-422, doi: 10.1109/IGARSS47720.2021.9553262.
.