Technology and satellite companies open up a world of data

Sampriya Roy remembers that it took her up to an hour to download a single 1-gigabyte image taken by the Landsat earth-imaging satellites.

That was in the late 2000s, when he was analyzing satellite imagery as part of his undergraduate studies at the Visvesvaraya National Institute of Technology in the Indian state of Maharashtra. And computer analysis of an image can take even longer. Sometimes Roy would start the analysis at night and it would continue the next morning as well.

Things are very different nowadays. Roy, who is a PhD student at Indiana University in Bloomington, uses a Google platform to store his data and run his algorithms and is capable of crunching thousands of images in minutes; All he needs is a web browser.

“It brings everyone on an equal playing field,” he says. In addition to data from US government sources such as Landsat, he uses sharp, detailed images from three commercial satellite companies to research coastal land loss in the Amazon region of Louisiana and Brazil – two of which were not present when he graduated. . .

Over the past few years, the technology and satellite companies’ offerings to scientists have increased dramatically. Thousands of researchers now use high-resolution data from commercial satellites for their work. use cloud-computing resources provided by large Internet companies to crunch thousands of data sets that would overwhelm most university computing clusters.

Researchers use new capabilities to track and visualize forest and coral reef loss; Monitoring of agricultural crops to increase yields; and predict glacier melting and disease outbreaks. Often, they are analyzing larger areas than ever before – sometimes involving the entire globe. Such studies are landing in leading journals and grabbing media attention.

Commercial data and cloud computing are not a panacea for all research questions. NASA and the European Space Agency carefully calibrate the spectral quality of their imagers and test them with specific types of scientific analysis in mind, while many commercial satellites are intended for governments and private customers to produce good quality, high-resolution images.

Have to take And no company can compete with Landsat’s free, publicly available, 46-year collection of images of the Earth’s surface. For commercial data, scientists must often request images of specific areas, taken at specific times, and agree not to publish the raw data. Some companies reserve cloud-computing assets for researchers with aligned interests, such as artificial intelligence or geospatial-data analysis.

And although companies publicly make some funding and other resources available to scientists, gaining access to commercial data and resources often requires a personal connection. Nevertheless, by choosing the right data sources and partners, scientists can explore new approaches to research problems.

Poverty mapping

Joshua Blumenstock, an information scientist at the University of California, Berkeley (UCB), is always on the lookout for data he can use to map wealth and poverty, especially in countries that do not conduct regular censuses. “If you’re trying to formulate a policy or do anything to improve living conditions, you generally need data to figure out where to go. To figure out who to help, even to find out what a difference the things you’re doing.”

In a 2015 study, they used records from mobile-phone companies to map Rwanda’s wealth distribution (J. Blumenstock et al. Sci 350, 1073–1076; 2015).

But to track wealth distribution around the world, it would have been impractical to stitch together data-sharing agreements with hundreds of these companies. Another possible information source – high-resolution commercial satellite imagery – could cost him upwards of US$10,000 for just one country’s data.

Blumenstock then learned that Facebook had purchased commercial satellite images for a program launched in 2014 to connect the global population to the Internet. After talks with a Facebook researcher on the project, he and the social-networking giant struck a deal.

Facebook will fund one of its graduate students to use the company’s technology to study how economic data from public surveys relates to the visual characteristics of buildings depicted in satellite data. Facebook, in turn, could potentially gain a sharper view of the socio-economic characteristics of rural areas, whose residents are less likely to have an Internet connection. (Facebook declined to comment.)

The arrangement, however, presented some challenges. Facebook sought a non-disclosure agreement before sharing the data. (Bluemenstock does not have access to personal Facebook user data, only satellite and other aggregates.