Title: ECHOSAT: Estimating Canopy Height Over Space And Time
Primary area: applications to physical sciences (physics, chemistry, biology, etc.)
Keywords: remote sensing, application, transformer, tree height, climate change, satellite, pixel-wise regression

Abstract: Forest monitoring is critical for climate change mitigation. However, existing global tree height maps provide only static snapshots and do not capture temporal forest dynamics, which are essential for accurate carbon accounting. We introduce ECHOSAT, a global and temporally consistent tree height map at 10m resolution spanning multiple years. To this end, we resort to multi-sensor satellite data to train a specialized vision transformer model, which performs pixel-level temporal regression. A self-supervised growth loss regularizes the predictions to follow growth curves that are in line with natural tree development, including gradual height increases over time, but also abrupt declines due to forest loss events such as fires. Our experimental evaluation shows that our model improves state-of-the-art accuracies in the context of single-year predictions. We also provide the first global-scale height map that accurately quantifies tree growth and disturbances over time. We expect ECHOSAT to advance global efforts in carbon monitoring and disturbance assessment. The produced height maps will be made accessible upon acceptance.

TL;DR: We present the first global temporal tree height map. Our map uses a novel loss function targeted at learning tree growth inherently from sparse labels.