Three-Dimensional Anaglyph of the Earth

At first glance, the map in front of you may seem rather ordinary. But, put on a pair of 3D glasses and see what happens. Mountains rise up and valleys recede, as this two-dimensional map appears to become three-dimensional. This map is the product of collaboration between the U.S. Geological Survey (USGS) Earth Resources Observation Systems (EROS) Data Center staff and researchers at several other institutions including the University of Minnesota. These scientists are creating innovative maps—both printed and digital—that make it possible to view Earth’s geographic features in unique ways. These visualizations become valuable tools for understanding complex geospatial relationships.

The data about land surfaces and coastal regions that was necessary to make this map was gathered by a satellite sensor called MODIS (short for moderate resolution imaging spectroradiometer). MODIS is carried aboard the National Aeronautics and Space Administration (NASA) Terra satellite, which is currently orbiting approximately 700 kilometers (435 miles) above the Earth’s surface. Techniques developed by USGS combine the MODIS satellite data with elevations of the land surface and seafloor. The result is this “global mosaic” that reveals the topographic features of our planet’s surface in remarkable detail. Seafloor data was derived from various declassified U.S. Navy sources. These sources include satellite altimetry observations combined with shipboard echo sounding measurements to ensure accuracy.

How is the 3D effect achieved? Using the data, two separate views of the Earth’s surface are generated, each at a slightly different perspective. These two views are color coded in red and blue and superimposed onto each other to make a type of picture called an anaglyph. It produces a three-dimensional effect when viewed through the corresponding red-and-blue colored filters of the special glasses.