Using Experimental Sites in Tropical Forests to Test the Ability of Optical Remote Sensing to Detect Forest Degradation at 0.3 - 30 M Resolutions

Using satellite remote sensing to map degradation in dense tropical forests is challenging. Accurate ground data are desperately needed to calibrate and validate detection algorithms. To improve our measurements of small-scale disturbance events, such as those caused by selective logging, we established a degradation experiment in eight 1-ha plots located in the tropical forests of Peru and Gabon. Biomass data was collected before and after the extraction of a small number of trees (resulting in the loss of between 4 and 31% initial biomass), and scenes of high-resolution optical satellite imagery from five satellites from 0.3 - 30 m pixel resolution compared before and after. Preliminary results suggest visual analysis of data up to and including 10m resolution (from Worldview-3 to Sentinel-2) can detect the disturbance caused by logging, but it is invisible to 30 m resolution Landsat. However, further work is needed to automate the detection process using high resolution data.