Eyes on Earth

The launch of Landsat 9 in September of 2021 represents a milestone for a joint USGS/NASA program that stretches back nearly 50 years. Landsat 9 will continue the legacy of unbroken, repeat Earth observations and contribute to our understanding of a changing planet. The primary USGS roles for Landsat satellites, which are built and launched by NASA, are to operate the ground system, process and archive the data, and distribute it to users around the world. On this episode of Eyes on Earth, we hear from two people who’ve been involved in the development of the Landsat 9 ground system to learn what it takes to bring Landsat data to the Earth and transform it into the data products and imagery we all recognize.

Satellite imagery is everywhere. We see it on TV news and weather coverage, in our Twitter and Facebook feeds, and on our phones’ mapping apps. The data behind that imagery is nothing like a screenshot, though. It’s comprised of tiny packets of data, broken down from huge files and digitally manipulated to resemble the surface of the Earth, a swirling storm system or a map of urban growth. Cloud computing resources can make it easier to work with huge datasets that cover long periods of time, which is why many remote sensing scientists are using it for their analyses. On this episode of Eyes on Earth, we hear from a scientist who used the cloud for a 150-year water use modeling project, and from a data scientist working to help train others to use cloud resources.

The Great Lakes represent roughly 20% of the surface freshwater in the world and 90% in the United States. The Great Lakes Basin supports more than 30 million people in the U.S. and Canada and 3,500 plant and animal species. The region faces threats that range from climate change and invasive species to pollution and development. Identifying and addressing those threats can be a daunting task, but for this episode of Eyes on Earth, we hear an example of how Landsat is helping address some of the restoration challenges.

Mapping land cover in the United States in the present isn’t a simple job, but satellites like Landsat make it possible. Mapping conditions in the pre-satellite era, which the LANDFIRE program does through its Biophysical Settings (BpS) GIS data products, is a far trickier proposition. BpS essentially offer a spatially-explicit map of pre-Colonial land cover in the U.S., alongside models that help scientists understand how landscapes re-grow and recover after disturbances. On this episode of Eyes on Earth, we learn how LANDFIRE went about creating its BpS datasets and the value they hold for land managers and fire scientists.

Urban heat islands occur in areas containing more impervious surfaces and fewer natural environments. The day and night surface temperature is higher in urban heat islands than in surrounding areas. During heat waves, this can lead to greater numbers of heat-related illnesses and deaths. Landsat satellites collect data on surface temperature and vegetative change that can help cities mitigate the heat stresses for residents, especially in a warming climate. For this episode of Eyes on Earth, we hear about how a mapping project involving Landsat data helped the New York City Council identify urban heat islands.