Lowcost Multispectral Vegetation Imaging System for Detecting Leaking CO2

As a component of a multisensor approach to monitoring carbon sequestration sites for possible leaks of the CO2 gas from underground reservoirs, a low-cost multispectral imaging system has been developed for indirect detection of gas leaks through observations of the resulting stress in overlying vegetation. The imager employs front-end optics designed to provide a full 50 ° field of view with a small, low-cost CMOS detector, while still maintaining quasi-collimated light through the angle-dependent interference filters used to define the spectral bands. Red and near-infrared vegetation reflectances are used to com-pute the normalized difference vegetation index (NDVI) and spatial and temporal patterns are analyzed statistically to identify regions of anomalous stress, which are then flagged for closer inspection with in-situ CO2 sensors. The system is entirely self-contained with an onboard compact computer and is housed in a weather-proof housing to enable extended outdoor deployment. © 2012 Optical Societ