Unlocking Landsat’s full potential: open dataįor a long time, Landsat data were locked up in bulky tapes in government data centers (Figure 1). The combination of visible and infrared bands relays valuable information to scientists about land cover, crop yield, and deforestation. This is because haze and thin clouds interfere more with data in visible than infrared wavelengths. What sets Landsat apart from our eyes is its ability to see in infrared wavelengths, which scientists use to more clearly distinguish land features such as wildfires or flooded fields. We can use Landsat observations in visible light to produce true-color images that capture how the land surface appears to the naked eye, much like how cameras work. Landsat images Earth entirely every 16 days, and its orbit is tuned to Earth’s rotation so that it always takes pictures in daylight, at midday. Similar to how you take a panorama by slowly moving your phone across a landscape, Landsat sweeps Earth from pole to pole. So, even orbiting thousands of kilometers above Earth’s surface, Landsat can resolve small land features like city neighborhoods and agricultural fields. Each pixel in a Landsat image corresponds to 30 meters by 30 meters on the ground, roughly the size of the baseball infield. Geological Survey (USGS) and NASA to image Earth’s land surface. The year of 1972 also marked the start of the successful Landsat program, which encompasses a series of satellites launched by the U.S. This article describes how satellite data can be used for geospatial studies, and how policies and technical advances over the years have facilitated these studies to bring maximal social benefits. New satellite technology allows us to generate images that capture these geospatial dynamics at much finer detail. White wispy clouds swirl above dark blue oceans and the Antarctic ice sheet, lush green tropical forests contrast with barren deserts and the fire-scarred African Sahel–this new perspective of Earth lets us see the interplay between geography, ecosystems, and humans at a continental scale. This snapshot marks the first time a person took a photo of Earth that neatly fits within the field of view. We have long been fascinated by space and the unknown, but here we stopped and looked back at our home. On December 7, 1972, the Apollo 17 crew captured the iconic “ Blue Marble ” photo, a bird’s-eye view of the Earth from 29,000 kilometers above ground.
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