STS-99 BENEFITS
Shuttle Radar Topography Mission

Science and Technology Applications

Geomorphology is the study of Earth's landscapes. These geologic formations are all around us standing as huge mountain ranges, carved deep into the Earth to form valleys and stretching flat across thousands of miles of land to create plains.

Plate boundaries cut through continents and oceans and are concealed by them. However, titanic geological events along these boundaries offer clues to their locations. Where plates converge, mountains and volcanoes are often found. Where they pull apart, oceans are born. Wherever they grind against each other, they are jostled by frequent earthquakes.

Digital topographic data of mountain ranges, which will be available for the first time with the retrieval of Shuttle Radar Topography Mission data, will allow geologists to test new models of how mountains form and determine the relative strength of the forces that uplift and crumple mountains and the erosive forces which polish and reshape them.

Lower resolution digital topographic data, available only in the last few years, have yielded some surprising results. It seems that landslides in mountainous areas are responsible for far more of the erosion than previously thought, causing revision of many basic ideas of mountain development. Even more surprising, models based on new digital data have shown that erosion of deep valleys into mountain ranges actually causes the adjacent peaks to rise in elevation due to the buoyant force of the underlying mantle.

This 3-D perspective of the remote Karakax Valley in the northern Tibetan Plateau of western China was created by combining two spaceborne radar images using a technique known as interferometry. Visualizations like this are helpful to scientists because they reveal where the slopes of the valley are cut by erosion, as well as the accumulations of gravel deposits at the base of the mountains.

As with most disciplines, archaeology has become more interdisciplinary, using cutting-edge technological tools in parallel with detailed field work. Increasingly, archaeologists are studying sites and human activity within their regional context to determine how the sites relate to each other and how they relate to the changing landscape.

This more regional view helps answer questions such as why cities and towns were built in particular locations, and how the patterns of settlement relate to natural resources in the area. To do this, it is important to look at why events occurred when they did, and how those events might have changed over time. Scientists are intensely interested in examining the interactions of people with the land they inhabited and exploited over time in an effort to explain the changes that occurred in both human societies and in the natural environment.

The Shuttle Radar Topography Mission will provide archaeologists with a topographic view of both ancient sites and the current landscape, which they can use to help determine the boundaries of original sites. Also, they will be able to learn how and where these sites fit into the regional landscape, as well as probable migration routes through topographic barriers such as mountain ranges.

Shuttle radar data also will enable them to compare large-scale ancient settlement patterns and their distribution around the world. Since many archaeologists working in remote parts of the world rely on outdated maps or no maps at all to conduct these studies, the Shuttle Radar Topography Mission's highly precise 3-D data will provide many with their first comprehensive tools.

Ecology concentrates on the interrelationship of living things and their environment. As civilization and technology advance, people have learned to modify the environment. Human activity has had enormous repercussions, changing ecosystems and depleting natural resources. People use vast amounts of energy and produce massive amounts of waste and exhaust. It is critical that scientists understand the impact humanity is having on planet Earth and that better tools be developed to accurately measure changes in world climate, temperatures, habitats and species.

SRTM data will be collected over all land surfaces that lay between 60 degrees north latitude and 54 degrees south latitude. The map shows all the regions where data will be collected. SRTM will not collect data over any of the areas in red.

Global climate change is another large-scale event occurring in the atmosphere, brought about by the increase of so-called "greenhouse gases" such as carbon dioxide. Like glass in a greenhouse, these gases admit the Sun's light but tend to reflect the heat that is radiated from the ground below back down to the ground, trapping heat in Earth's atmosphere.

Scientists continue to work on computer models of climate change to determine how much of an increase in greenhouse gases is occurring in Earth's atmosphere. Shuttle Radar Topography Mission data will allow them to develop more accurate models of the global circulation of the atmosphere.

Mapping of the world's rainforests is an essential ingredient in global protection of Earth in the next century. Another avenue of investigation during the Shuttle Radar Topography Mission will focus on radar-imaging of fragile habitats, such as Earth's tropical forests, to assess vegetation types and determine terrain characteristics. Terrain data that will be collected during the Shuttle Radar Topography Mission will provide near-global-scale coverage of these ecosystems at a much higher resolution and allow scientists to study tropical rainforests in more detail. Combined with data from other remote sensing satellites, 3-D data of landforms, waterways and other types of vegetation will contribute to their understanding of a region's overall health.

Communities nestled near the bases of active volcanoes or on earthquake faults will be of interest to volcanologists and seismologists as well. Scientists can use 3-D topographic maps to study the potential of natural hazards. In addition to volcanic eruptions and earthquakes, regions prone to severe flooding by major rivers will be of interest.

Radar imaging will be used as a tool for city planners, land management and resource conservation efforts, which require highly detailed topographic maps for monitoring land use patterns. Spaceborne radar imaging systems can clearly detect the variety of landscapes in an area, as well as the density of urban development. Examples of previous land management surveys included imaging of major world cities, such as Los Angeles, New York and Washington, D.C.

Commercial Applications

Some of the commercial products that will be possible using Shuttle Radar Topography Mission data will benefit the transportation industry and the communications and information technologies markets. In telecommunications, wireless service providers and operators will be particularly interested in this digital elevation data. Topographic data can be used for building better transceiver stations and identifying the best geographic locations for cellular telephone towers.

Companies conducting geological and mineral exploration, as well as hydrological and meteorological services, including risk assessment, also will be interested in the data. Providers of tourist and leisure maps, satellite data and virtual reality software also will reap the benefits of these data, which can be integrated into an absolute geographic grid system that will make all data products uniform and consistent. In fact, just about any industry that requires accurate digital elevation data stands to benefit from this mission.

An X-SAR image of Honolulu, Hawaii at 21 degrees 34 minutes north latitude and 157 degrees 88 minutes west longitude.

Terrain-height data may also be a valuable addition to current aircraft navigational tools to assist pilots in takeoffs, landings and pinpointing their locations during flight. Ground collision avoidance systems will become far more accurate with new measurements and topographic maps of Earth's terrain derived from the Shuttle Radar Topography Mission. Flight simulators for crew training will have realistic backgrounds and, by adding information from inflight global positioning system receivers, will become state-of-the-art reference systems, giving pilots a set of "virtual eyes" for use in bad weather or at night.

Automobile navigation displays and digital road maps also will benefit from terrain information provided by the Shuttle Radar Topography Mission. Here terrain height is required, combined with accurate data about the horizon. The newly acquired data will be made available to commercial users and tailored to their specific needs.

Defense Applications

The National Imagery and Mapping Agency (NIMA) plans to use the digital global terrain elevation maps for planning, rehearsal, modeling and simulation for military and civilian uses. Successful completion of the SRTM data set will provide NIMA with coverage of most of Earth's populated land areas, with three times better resolution than previously available.

Additional information about Defense Department applications is available from NIMA, a partner in the Shuttle Radar Topography Mission.

Uses of this data include improved water drainage modeling, more realistic flight simulators, better locations for cell phone towers, navigation safety and even improved maps for backpackers.