ARTISANAL MINING RIVER DREDGE DETECTION USING SAR IN GUYANA

This project utilizes Synthetic Aperture Radar (SAR) remote sensing to identify and monitor small-scale gold mining dredges operating on the rivers in Guyana, South America. River dredging is an elusive activity often carried out by individual actors that can be difficult to monitor due to remote operating areas, consistent movement, and excessive cloud cover common to South America. High resolution optical satellite imagery is of limited utility in monitoring dredge activity due to the small spatial footprint of the dredges themselves, the cloud coverage common throughout much of South America, and the time-consuming nature of manual identification methods. SAR is an active remote sensing technology that uses longer wavelength signals (between 2 – 100 cm) that are unaffected by weather and can be collected day or night. SAR wavelengths that interact with manmade objects, such as river mining dredges, create strong backscatter signals compared their surrounding environment. These high intensity signals can be statistically identified and then extracted using semi-automatic techniques adapted from ocean ship detection methods. This study implements a local thresholding method for target detection and elimination of false alarms through decision rules to produce a dataset of potential dredges to map artisanal gold mining activity on the spatially narrow and braided river channels of Guyana. Dredge identification through these techniques provides timely and actionable information about riverine mining activity to aid authorities who monitor mining regulations and environmental impacts.