LandTrendr and TimeSync

These tools are used in tandem to detect trends in forest disturbance and recovery. LandTrendr (Landsat-based detection of Trends in Disturbance and Recovery) is a mapping tool that automatically extracts information on land surface changes (e.g., fire, insect and disease damage, timber harvesting or regrowth) from Landsat satellite imagery. TimeSync is a companion image interpretation software tool for synchronizing algorithm and human interpretations of Landsat imagery. These tools capture both short-duration events such as harvest and fire, and long-term trends such as declines in forest health and regrowth. Researchers can use these new tools to comprehensively map change over every Landsat pixel (30 m) since 1972 in forested ecosystems and understand the accuracy of the maps.

Most points on the Earth's surface have a "life history" captured in images taken by the Landsat Thematic Mapper instruments. With LandTrendr, we use statistical algorithms to separate trends from noise, and thereby identify periods of stability and of change for every pixel (30 by 30 meters in size). This process of trajectory segmentation is the core of all our mapping. The trajectory segmentation phase is preceded by substantial "pre-processing" needed to ensure that the data are clean enough to discern trends, and is followed by several different types of "post-processing" that make the maps ultimately of interest to most users.