Remote Sensing & Spectral Measurements
We have a long-standing interest in using measurements of the optical properties of foliage – i.e., reflectance and absorbance of both fresh and dried tissue across the visible/near-infrared spectrum—to monitor vegetation health, quantify impacts of chronic stress, and determine foliar chemical composition including pigments, mineral nutrients, and fiber constituents (e.g. lignin and cellulose).
We also draw on data from a variety of airborne and satellite remote sensing platforms. For example, MODIS (MODerate resolution Imaging Spectrometer, image courtesy of Jeremy Fisher) provides global coverage of the earth’s surface at a relatively high temporal resolution (daily, with 8 or 16 day composite products) but coarse spectral resolution. By comparison, AVIRIS provides hyperspectral data (400 to 2500 nm at a spectral resolution of 10 nm) at relatively fine spatial resolution, but only at a single point in time. We have used MODIS data in our phenology studies (in conjunction with researchers from Boston University), and AVIRIS data to study spatial variability in canopy chemistry (in conjunction with researchers from the University of New Hampshire).