Harnessing rich satellite data to estimate crop yield
16 August 2017
Without advanced sensing technology, humans see only a small portion of the entire electromagnetic spectrum. Satellites see the full range—from high-energy gamma rays, to visible, infrared, and low-energy microwaves. The images and data they collect can be used to solve complex problems. For example, satellite data is being harnessed by researchers at the University of Illinois for a more complete picture of cropland and to estimate crop yield in the U.S. Corn Belt.
The study uncovers that the many satellite data sets share common information related to crop biomass grown aboveground. However, the researchers also discover that different satellite data can reveal environmental stresses that crops experience related to drought and heat. Guan says the challenging aspect of crop observation is that the grain, which is what crop yield is all about, grows inside the canopy, where it isn't visible from above. "Visible or near-infrared bands typically used for crop monitoring are mainly sensitive to the upper canopy, but provide little information about deeper vegetation and soil conditions affecting crop water status and yield," says John Kimball from University of Montana, a long-term collaborator with Guan and a coauthor of the paper.
Image credit: NASA - Satellite constellation for collecting data on crop yield