By John R. Hughes, editorial director, Earth Imaging Journal (www.eijournal.com), Greeley, Colo.
Exactly who uses Landsat satellite imagery and what value do they derive from the information?
In the first study of its kind, U.S. Geological Survey (USGS) investigators at the Fort Collins (Colo.) Science Center surveyed a broad cross section of Landsat users to answer such questions. The short answer is that a range of customers”academics to foresters and urban planners to agricultural managers”use Landsat satellite imagery in a wide variety of applications.
Landsat imagery is readily seen as a scientifically unbiased, policy neutral source of information, says USGS Director Marcia McNutt. When people from varied professional backgrounds and with different technical skills can all examine and understand the same image, the decision-making process becomes more objective and more inclusive. The significance of this study is in accurately identifying who uses Landsat and why.
More than 2,500 users of satellite imagery, including almost 1,400 current users of Landsat imagery in private, academic, government and nonprofit sectors, participated in the 2009“2010 survey. Respondents were surveyed about their use of satellite imagery, including Landsat, and what the impact would be without access to Landsat imagery.
The results of the survey revealed that respondents from multiple sectors use Landsat imagery in many different ways, as demonstrated by the breadth of project locations and scales, as well as application areas. The value of Landsat imagery to these users was demonstrated by the high importance placed on the imagery, the numerous benefits received from projects using Landsat imagery, the negative impacts if Landsat imagery was no longer available and the substantial willingness to pay for replacement imagery in the event of a data gap.
Each of 37 different application areas investigated”from agriculture and environmental management to education and disaster response”were primary uses for some respondents. More than 91 percent of respondents who currently used Landsat imagery used it to answer questions or solve problems, and 57 percent reported using the imagery as a basis for decisions. More than 80 percent said the imagery is somewhat or very important to their work.
Remotely sensed Landsat images aren't just pictures; they contain many layers of data collected at different points along the visible and invisible light spectrum. Among a multitude of possible applications (see table at left), the data can be interpreted to reveal what types of vegetation are present, the status of soil and vegetation or how a natural disaster has impacted an area.
Landsat provides valuable data for land use research and advances the U.S. Department of the Interior's important role in land remote sensing under President Obama's National Space Policy. The policy articulates the president's commitment to reinvigorating U.S. leadership in space and maintaining space as a stable and productive environment for the peaceful use of all nations. Landsat images are unique in that they provide complete global coverage, they're available for free, and they span nearly 40 years of continuous Earth observation. No other satellite imagery has that combination of attributes.
Although the survey results supply a wealth of information on their own, they can also be built upon through further research to generate a more complete picture of the population of Landsat users as a whole. The complete report, The Users, Uses, and Value of Landsat and Other Moderate-Resolution Satellite Imagery in the United States”Executive Report, is available online at http://pubs.usgs.gov/of/2011/1031