NASA’s Landsat program has been responsible for some amazing imagery of our tiny little planet along with an unparalleled data archive. It is the longest-running continuous space-based record of Earth in existence. For over 40 years, the Landsat program has collected spectral information from Earth’s surface, creating a historical archive unmatched in quality, detail, coverage, and length. The program’s more than 9 million images have been used in more than 18,000 scientific papers, according to NASA’s Earth Observatory.
Landsat data also provides invaluable data for agriculture, from tracking crop production to assessing crop health and monitoring water use. Hundreds of miles above the Corn Belt, NASA satellites provide critical views of the region. David Johnson, who works for the National Agricultural Statistics Service (NASS) is a geographer and also a member of the Landsat science team. He says that Landsat imagery is crucial to the information NASS provides to farmers and consumers. “Once we establish what we think is growing in each field, we aggregate that to come up with a statistic for the amount of corn area in a state like Iowa, or soybean area in a state like Illinois, or wheat in their state like Kansas. It’s really for all the states, all the crops,” says Johnson.
According to Jim Irons, Director of NASA’s Earth Sciences Division, when the first Landsat satellite was launched in 1972, it occurred just after an event that became known as the “Great Grain Robbery.” In 1972, drought and crop failures led the Russians to begin buying up foreign wheat, purchasing 10 million tons from the U.S. by August. As it turned out, the shortage in Russia was part of a worldwide shortage in grain production that almost wiped out international stockpiles. Clifton Luttrell wrote in the Federal Reserve Bank of St. Louis Review in 1973 that the U.S. government did not recognize this as it was happening because the government did not have a big-picture view of agricultural output worldwide.
As federal grain subsidies continued to favor bargains for the Soviets buying American wheat, the price of domestic grain rose sharply, causing a food price crisis back home. Global food prices rose at least +30%, and grain stockpiles were decimated. U.S. farmers also probably got a very raw deal since the nation wasn’t aware of the problem in the rest of the world and sold the grain from our storage at a very low price. At that point, sophisticated agricultural monitoring was only in its infancy. According to Gary Weir of the National Geospatial-Intelligence Agency, despite using satellites to photograph grain-growing areas, the resolution was not clear enough to reveal much information on the health of crops.
Valerie Thomas, retired associate chief of the Space Science Data Operations Office, managed the development of early Landsat image processing software systems. One of her earliest projects was the Large Area Crop Inventory Experiment, known as LACIE. It was a study to determine if test sites of wheat fields in certain locations could be identified in Landsat images, and then be used during the growing season to predict wheat yield. The joint effort with NASA, National Oceanic and Atmospheric Administration (NOAA), and the Department of Agriculture, showed for the first time that global crop monitoring could be done with Landsat satellite imagery.
Today, Landsat data is used to make countless decisions that impact food and water management. The data enable people to analyze the health and vigor of crops as they mature over the growing season; the needs of specific fields for fertilizer, irrigation and rotation; planted acreage to forecast crop production and fight crop insurance fraud; how much water is used in irrigation; and the impacts of drought. NASA is getting ready to launch the ninth set of Landsat satellites this fall. The satellites are largely replicas of their Landsat 8 predecessors but do add two new science instruments that researchers say will enhance our ability to measure changes on global land surface at a scale where we can separate human and natural causes of change.
In the run-up to the Landsat project’s 50th anniversary, NASA’s Earth Observatory is running a public competition to choose the best Landsat pictures of all time. I included some of the 16 images currently in the running below. Check out the rest HERE. (Sources: NASA, Life Science, USGS)
