Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 3, 2011
Publication Date: July 8, 2011
Citation: Kustas, W.P., Anderson, M.C. 2011. Thermal sharpening in agricultural environments and the utility of high resolution HyspIRI thermal data [abstract]. Hyperspectral Infrared Imager Science Symposium on Ecosystem Data Products. http://hyspiri.jpl.nasa.gov/documents/2011-symposium-symposium-agenda-and-presentations.
Many agricultural fields in Europe and developing countries are relatively small on the order of 1- 10 hectares, and even though in the U.S. agricultural fields tend to be larger, the resolution of thermal-infrared temperature (TIR) sensors from operational satellites are still generally too coarse at 100 to 1000 m in spatial resolution. Although with the 100 m TIR sensor on board Landsat 5 provides a more desirable resolution for discriminating individual fields, it has repeat coverage every 16 days. Considering cloud cover, this TIR information is too infrequent and hence has limited utility for monitoring evapotranspiration (ET) in irrigated agricultural areas. Given the fact that irrigated agriculture uses up to 70% of the available water in arid and semiarid regions, it is imperative that ET from agricultural fields be monitored, particularly in water limited regions. Techniques at sharpening coarser resolution TIR data (~1000 m) having more frequent coverage (e.g., daily such as MODIS) are useful under some conditions, but are not reliable when trying to capture the affect of soil moisture variations due to irrigation at the field scale. With HyspIRI TIR spatial resolution (~60 m) and 5 day return cycle, sharpening the TIR imagery to sub-field scale might be quite feasible using the more slowly evolving and changing vegetation cover conditions that can be mapped using Landsat or ASTER visible./near-infrared observations. This could provide reliable thermal sharpened imagery on a much more frequent basis. Examples of applying TIR sharpening techniques at various resolutions over agricultural fields in the U.S will show how sharpening improves visual information content for monitoring ET.