Exploring the detection of bark beetle attacks in Norway spruce forests in sentinel-1 image time series

In this study, we explored the use of long time series of Sentinel-1 SAR images for the detection of bark beetle outbreaks in temperate forests. Bark beetle attacks induce a gradual deterioration in the health of trees, ultimately leading to their death. Accordingly, time series of remote sensing data are crucial to detecting them. In this study, time series of Sentinel-1 data were collected in reference areas attacked by bark beetle in the period 2019-2022 and then the backscatter values were extracted and analyzed. A method for the automatic detection of bark beetle attacks has been developed and tested on the same polygons. The preliminary results showed that the distribution of the Sentinel-1 backscatter values in VV and VH polarizations inside the attacked polygons before and after that attack is significantly different. The detection method achieved a detection accuracy above 65% for all the dates considered