Since 2009, the USDA's National Agricultural Statistics Service, or NASS, has drawn on Landsat data to monitor dozens of crops in the lower 48 states as part of NASS's Cropland Data Layer program. The Cropland Data layer uses Landsat and similar sensors to identify what crop is growing where in the country. Separately, NASS uses NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) instruments aboard the Aqua and Terra satellites to monitor daily vegetation health and growth stage, all indicators of crop yield.
“Landsat has been one of the only ways we can directly measure the global food supply,” said Brad Doorn, program manager for NASA's Applied Sciences Water Resources and Agriculture Research at NASA Headquarters in Washington, D.C. However, “It's not all satellites,” Mueller said.
During a typical farming year, NASS relies heavily on their ground observations and surveys data. Across the country, NASS field officials visit farms, and measure acreage and condition of planted fields throughout the growing season. NASS also receives crop acreage data from the Farm Service Agency (FSA). Farmers are required to self-report crop acreage and land use information to FSA annually. FSA uses the data to determine payment for federal programs such as crop loss due to natural disaster or financial loss from changes in market prices.
NASS will publish the final Cropland Data layer in January of the following year and makes the data available to everyone through the CropScape website. Disaster managers use the sites historic data to evaluate crop damage from this year's floods and other natural disasters. Resource managers use historic data to direct crop rotation, study land-use change, and monitor water use.
The U.S. Department of Agriculture tracks how many acres and the annual yield for every crop produced. One method used to estimate crop acreage and yield is remote-sensing data from the NASA-USGS Landsat satellite program. The program started in 1997,with North Dakota, and by 2008 covered the entire lower 48 states and the District of Columbia.
Music: "Downloading Landscapes" by Andrew Michael Britton [PRS] and David Stephen Goldsmith [PRS]. Published by Atmosphere Music Ltd [PRS].
Farmers rely on the accuracy of a crucial NASA and USGS mission, Landsat, to make decisions about crops. In this video, you can hear Landsat's view of crops from space in the form of a song, called a data sonification. Every sound carries meaning. Six notes of an acoustic guitar indicate the current top six crops by acreage, in order: corn, soybeans, wheat, alfalfa, cotton and sorghum. In each year, the pitch of these notes indicates the acreage recorded by Landsat for those six crops. Higher pitches indicate more acreage, and a low percussive sound distinguishes each year.
Video and data sonification produced by System Sounds for NASA's Curious Universe podcast.
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 188.8.131.52.0