A combined effort between researchers at the Carnegie Mellon University Robotics Institute, the U.S. Geological Survey (USGS) and Google provides users with easy access to 13 years of NASA Landsat imagery of the Earth’s surface. The new capability within Google Earth Engine lets users zoom in and out on any spot on the globe, moving back and forth in time between 1999 and 2011.
Although access to the Landsat program’s Earth imagery has been available to the public since 2008, the process of acquiring it has been difficult and cumbersome, due to the sheer volume of data involved.
Google has provided a solution to this problem through the creation of the world's largest library of hard-drive-based Landsat imagery, with more than 1.5 million images; it is a collection that is growing by thousands of images per day. Rebecca Moore, engineering manager of Google Earth Engine, said “The sheer volume of visual data is daunting to explore by conventional means … Together we can offer an intuitive, effortless method to explore the planet in space and time."
The new tool for Earth Engine is based on Carnegie Mellon’s GigaPan Time Machine technology. Originally built for use with GigaPan panoramic photographs, the program utilizes a special feature of HTML5 language, allowing for the development of a software architecture which makes it possible to smoothly shift from one video section to another. It does this without the requirement of plug-ins such as Adobe Flash.
When this is combined with the massively parallel computation power of Google’s Earth Engine, the image archive is transformed into zoomable videos that can be accessed with ease through a modern web browser.
Randy Sargent, a system scientist in the Robotics Institute's CREATE Lab in Pittsburgh, commented on the significance of the new tool, predicting that it will help ground public discussions regarding land use, climate change and environmental policy. He stated “You can continue to argue about why deforestation has happened ... but you no longer will be able to argue whether it happened.”
Video demonstrations can be viewed on the Google Earth Engine website, and those using the Chrome and Safari web browsers can try out the time-lapse tool now. More information is available in the video below.