Geographic Information Systems (GIS)
What is GIS?
GIS is a collection of computer-based tools for organizing information from a variety of data sources to map and examine changes on Earth. It is designed to capture, store, manage, analyze, and visualize all types of geographical data. GIS allows for the integration and collective analysis of geospatial data from multiple sources, including satellite imagery, GPS recordings, and textual attributes associated with a particular space.
GIS is used in nearly all fields that need to understand the spatial patterns and relationships between different datasets, from land-use planning to emergency response to resource management.
Want to Learn More?
GIS includes many components:
- visualizations through interactive maps,
- data based on the location of features or variables represented,
- spatial analytic functions that focus on identifying trends and patterns across space and time, and
- applications that enable tools and services in user-friendly interfaces.
Geospatial data are collected in a variety of ways. It is remotely sensed from instruments aboard airplanes and satellites, created from imagery, or captured in the field.
GIS data contain spatial coordinates to represent where features are located. This is typically done using latitude (y) and longitude (x) coordinates. Multidimensional data can include additional dimensions such as depth, elevation and/or time (z).
NASA's Earth Observing System Data and Information System (EOSDIS) archives and distributes 41.86 petabytes (PB) of Earth observation data. This scientific data are often complex and rich with valuable information across multiple dimensions beyond time and space.
Multidimensional data and its associated metadata are stored in scientific data formats optimized for these data types. The most common specialized formats are Network Common Data Form (netCDF), Hierarchical Data Format (HDF), and Gridded Binary (GRIB). Some of the more common cloud-ready formats include Cloud Optimized GeoTIFF (COG), Meta Raster Format (MRF) and Cloud Raster Format (CRF). These scientific data formats share common structures for storing multiple variables, with each variable being a multidimensional array.
GIS tools rely on information stored in data files to determine the correct method of visualization. Often, this relies on the Coordinate Systems (the values used to define a position within a spatial reference to represent location when capturing the data), as well as the Projections (how the values are located and displayed on a map).
At NASA, our scientific data work well in GIS tools if it follows standards such as the Hierarchical Data Format - Earth Observing System (HDF-EOS) and conventions such as Climate Forecast (CF). These help to ensure the data is formatted in a way for tools to read and write. However, not all of the complex, scientific data can be easily read or understood by libraries such as the Geospatial Data Abstraction Library (GDAL), which tells software what information to parse from data files and how to display them properly.
Using GIS tools, users can perform a multitude of spatial analyses to determine patterns or trends across space. GIS analysis is used to detect change, extract features, identify relationships, interpolate data, calculate statistics, determine viewsheds, and find optimal routes. GIS tools also help researchers employ machine learning and deep learning models to enhance our use of big data and make more accurate predictions.
GIS tools do more than make maps. Although cartography is the foundation for GIS technology, modern technology allows GIS practitioners to create and publish web mapping services, develop powerful user-intuitive applications, create interactive dashboards, and tell effective stories with data alongside narration and media. These methods allow content to be distributed to broad audiences in ways that are easy to digest, explore, utilize as well as integrate with content of their own. Expanding beyond traditional maps allows NASA to increase awareness and exposure within new communities and aids in the understanding and use of science data.
GIS at NASA Earth Science
Our vision is to identify and deliver high value Earth Science data in formats compliant and compatible with GIS standards; to ensure data are interactive, interoperable, accessible, and GIS-enabled through primary GIS platforms; and to provide the maximum impact to research, education, and public user communities requiring visualization and spatial analysis.
Data and Services
NASA data are freely and openly available to researchers and the public at large. Earthdata Search provides the means for discovery, filtering, visualization, and access across all of NASA’s Earth science data holdings. This includes more than 33,000 Earth observation data collections. It allows you to search by any topic, collection, or place name.
|NOTE: NASA data are available in a number of various scientific formats, however, not all data are GIS-ready, and not all files can be easily ingested into GIS systems without error or complications. Visit the Earthdata Forum to interact with NASA subject matter experts who can answer any questions that may arise.|
Interactively browse and download full-resolution, global satellite imagery from over 900 data products with Worldview. Showing the entire Earth as it looks "right now"—or at least as it has looked within the past few hours—Worldview supports time-critical application areas such as wildfire management, air quality measurements, and weather forecasting. Geostationary imagery layers are also now available. These are provided in ten minute increments for the last 30 days. These full disk hemispheric views allow for almost real-time viewing of changes occurring around most of the world. Worldview is supported by NASA’s Global Imagery Browse Services (GIBS).
GIBS provides access global, full-resolution imagery from over 900 satellite imagery products via a variety of standards-based set of web services, such as Web Map Tile Services (WMTS), Tiled Web Map Service (TWMS), Web Map Services (WMS), and Keyhole Markup Language (KML).
NASA also utilizes Esri’s ArcGIS Online—a collaborative web GIS that allows users to use, create, and share data, layers, maps, applications, and analytic products. NASA’s publicly available content includes web services, dashboards, notebooks and story maps.
Selected authoritative content is also registered to Esri’s Living Atlas of the World, which now features imagery layers provided by EOSDIS.
Tools and Applications
There are a number of GIS tools from which data can be visualized, subsetted, and downloaded in different file formats that are GIS analysis-ready. There are also several Geospatial services (specifically, web map services [WMS], web feature services [WFS], and web coverage services [WCS]) providing access to a variety of GIS-ready datasets.
GIS in Action
Ready to get started?
A GIS Pathfinder was developed to provide a guided walkthrough of NASA data in GIS tools. This resource provides links to the tools from which data can be visualized, subset, and downloaded in different file formats, as well as a brief tutorial on using the tool to access NASA geospatial web services.
NASA's Earthdata data discovery and data access webinars span the Earth science disciplines and are designed to help users learn about NASA EOSDIS data, services and tools and show users how to work with these resources.
Already on Your Way?
If you are using NASA earth observation data, you may need some help navigating the complexities. NASA's EOSDIS has Tutorials/How-To Guides and Data Recipes to help you navigate the complexities of data processing and transformation to GIS use. If you are interested in receiving expert advice, check out the Earthdata Forum. Within the “Search by Tags” box, under “Services/Usage” select “GIS Tools” from the dropdown. Here, subject matter experts from several of NASA's Distributed Active Archive Centers (DAAC) can discuss general questions, research needs and data applications. Users can query how to access, view and interpret the data.
We’d love to hear from you! Feedback from user communities is extremely valuable. Understanding your data needs to include what format, distribution method, and application or tool used to work with the data will help us improve our services.
Page Last Updated: Jul 12, 2021 at 12:23 PM EDT