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In 2014, Planet, a company based out of San Francisco, California, began launching its miniature satellites into space. Known as "Doves," these satellites orbit around Earth as a "flock" every 90 minutes and provide snapshots of Earth's surface daily at a three-meter footprint. These satellites are revolutionizing the Earth observation sector.

In South Dakota State University's Geospatial Sciences Center of Excellence, researchers are utilizing Planet's satellite data to reveal key insights into the Western United States.

The Western U.S. is home to a growing population and is characterized by a predominantly semi-arid climate. Detecting plant growth cycles from remote sensing data—satellite data—had previously been a significant challenge in semiarid regions, mainly due to the irregular growth cycles and vegetation concentrations. Semiarid climates have highly variable rainfalls, and the vegetation—mainly grasses, shrubs and drought-tolerant trees—is unevenly distributed across the landscape.

In a study in ISPRS Journal of Photogrammetry and Remote Sensing, SDSU researchers have demonstrated the effectiveness of the Planet's satellites and data in accurately detecting plant growth cycles in the Western U.S. They found that high spatial resolution plant data can capture irregular plant growth and separate the growth cycles of different types of plants.

"Given the growing ecological importance of semiarid ecosystems, it is pressing to improve our understanding of vegetation phenological dynamics and their response to climate variations," said Xiaoyang Zhang, SDSU Distinguished Professor and co-director of the Geospatial Sciences Center for Excellence.

The ability to accurately detect plant growth cycles in these climates will inform optimal planting and harvest times. It will also aid in drought response strategies and forage availability for livestock. Combined, this information will lead to better production security and resource management in areas with highly variable levels of precipitation.

"Our results highlighted the promising potential value of Planet's satellite data for investigating plant-specific phenology with high temporal and high spatial resolutions in semiarid ecosystems," explained Yuxia Liu, postdoctoral research associate in the Geospatial Sciences Center of Excellence.

The researchers validated Planet's satellite data with ground-level imagery via infrared-equipped digital cameras at 15 different sites in the Western U.S.