What’s the Big Idea? — Charting Change from the Skies
May 11, 2016 • Tom Loveland, research scientist with the USGS Earth Resources Observation and Science Center, explains how he uses data — both past and present — to help scientists, natural resource managers, and the public better understand how the face of the planet is shifting and what that change means.
I’m Tom Loveland. I am a research scientist with the USGS EROS Center, Earth Resources Observation and Science Center in Sioux Falls, South Dakota.
We have a forty-three…a forty-three and a half year long record of observations to provide the definitive condition of the state of the planet. Our initiative now is to take that entire archive, apply advanced statistical approaches, and to try to convert it into meaningful information of what the earth is made of, how the condition is changed, how the uses have changed, and what the consequences of what those changes are to natural systems and people.
There are two fundamental audiences that we are trying to contribute to. One is the scientific side that is trying to understand the linkage between human activity and changes in the global climate systems. The second are the natural resource managers that have to make the day-to-day decisions on the threats to their lands and how to better manage them. How what’s going on in their backyard relates to the region they are working in and so we can provide the local context for those kinds of assessments. The instruments we use are orbiting satellites. In particular, we rely on the satellite series called the Landsat. They’ve been around since 1972.
To analyze that very large record of many petabytes of data, we rely upon computer based algorithms that help us characterize and classify those types of information that we use. Landsat, there have been seven successful missions and I would have to say that the changes from 1972 to the present have revolved around evolutionary changes and electronic imaging capabilities. Landsat hasn’t revolutionized, its evolved. Mainly because of the primary goal of maintaining continuity of measurement. Our latest satellite for example, that was launched two years ago, has an improved instrumentation that allows us to detect very subtle features and subtle changes on the earth that were unmeasurable on previous satellites, mainly due to the improvements and imaging capabilities
The big things we’re trying that challenge us is the growing worldwide users of Landsat is huge. We send out so many more images per day than we ever did in our history, and so modernizing our distribution systems and ensuring that the quality of data that we are sending out is high, that’s a top priority.
The other thing, though, is growing the infrastructure for computing the IT capabilities we need systematically analyze the massive treasure of observations.
I have spent my career studying changes in land use and land cover using satellites. I was introduced to it in 1972, right before the first Landsat was launched and I took a university course in remote sensing and that really provided me with the insight that we have a tool that can help us understand how the planet is changing and so I worked on that throughout the year and many years working from global to local scales and everything in between and it’s just an important part of understanding what’s changing on this planet.
The fact is, we can now harness the entire archive and extract information that we couldn’t before when we were limited to the small volumes of observation we use. We now are simultaneously analyzing a full record, not portions of records.
Tom Loveland is a research scientist with the USGS Earth Resources Observation and Science Center