NASA World Wind

Animation showing atmosphere and shading effects in v1.4

USGS Urban Ortho-Imagery of Huntington Beach, California in older version of World Wind (1.2)

Rapid Fire MODIS - Hurricane Katrina

A cyclone moving across the Indian Ocean (on normal cloud cover - not Rapid Fire MODIS)

Moon - Hypsometric Map layer

Mars (THEMIS layer) - Olympus Mons

Hurricane Dean in NASA World Wind

Washington DC, Wikipedia point layer - icons link to Wikipedia articles

World Wind is an open-source (released under the NOSA license) virtual globe first developed by NASA in 2003 for use on personal computers and then further developed in concert with the open source community since 2004. As of 2017 a web based version of World Wind is available online,^[1] in addition an Android version is also available.^[2]

The original version relied on .NET Framework, which ran only on Microsoft Windows. The more recent Java version, World Wind Java, is cross platform, a software development kit (SDK) aimed at developers and, unlike the old .NET version, not a standalone virtual globe application in the style of Google Earth. The SDK includes a suite of basic demos, available at goworldwind.org.^[3] The World Wind Java version was awarded NASA Software of the Year in November 2009.^[4] The program overlays NASA and USGS satellite imagery, aerial photography, topographic maps, Keyhole Markup Language (KML) and Collada files.

Overview

Though widely available since 2003, World Wind was released with the NASA Open Source Agreement license in 2004. The latest Java-based version (2.1.0), was released in December 2016.^[5] As of 2015 a web based version of World Wind is under development^[6] and available online.^[7] An Android version is also available.^[8]

The previous .NET-based version was an application with an extensive suite of plugins. Apart from the Earth there are several worlds: Moon, Mars, Venus, Jupiter (with the four Galilean moons of Io, Ganymede, Europa and Callisto) and SDSS (imagery of stars and galaxies).

Users could interact with the selected planet by rotating it, tilting the view, and zooming in and out. Five million place names, political boundaries, latitude/longitude lines, and other data can be displayed. World Wind.NET provided the ability to browse maps and geospatial data on the internet using the OGC's WMS servers (version 1.4 also uses WFS for downloading place names), import ESRI shapefiles and kml/kmz files. This is an example of how World Wind allows anyone to deliver their data.

Other features of World Wind.NET included support for .X (DirectX 3D polygon mesh) models and advanced visual effects such as atmospheric scattering or sun shading.

The resolution inside the US is high enough to clearly discern individual buildings, houses, cars (USGS Digital Ortho layer) and even the shadows of people (metropolitan areas in USGS Urban Ortho layer). The resolution outside the US is at least 15 meters per pixel.

Microsoft has allowed World Wind to incorporate Virtual Earth high resolution data for non-commercial use.^[9]

World Wind uses digital elevation model (DEM) data collected by NASA's Shuttle Radar Topography Mission (SRTM), National Elevation Dataset (NED) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). This means one can view topographic features such as the Grand Canyon or Mount Everest in three dimensions. In addition, WW has bathymetry data which allows users to see ocean features, such as trenches and ridges, in 3D.

Many people using the applications are adding their own data and are making them available through various sources, such as the World Wind Central or blogs mentioned in the link section below.

All images and movies created with World Wind using Blue Marble, Landsat, or USGS public domain data can be freely modified, re-distributed, and used on web sites, even for commercial purposes.

Add-ons and plugins

World Wind can be expanded by using one of many add-ons - small extensions that add new functionality to the program.
Possible types of add-ons:

• Point layers - simple XML files displaying placemarks (point of interest) as icons
• Trail layers - paths (routes, boundaries)
• Line features - XML with a list of points visualized as a line or wall
• Polygon features - XML with a list of points visualized as a filled polygon (flat or extruded)
• Model features - XML used to load 3D textured meshes
• Place names - specific points (such as cities, hills and buildings) that are assigned text labels
• Image layers - high resolution imagery for various places in the world
• Scripts - files that control camera movement

Plugins are small programs written in C#, VB or J# which are loaded and compiled by World Wind at startup. Plug-in developers can add features to World Wind without changing the program's source code.

World Wind Java

The original recipe for World Wind was restricted to Windows, relying on the .NET libraries and DirectX. A new SDK version has been developed in Java with JOGL referred to as World Wind Java. The latest version (2.1.0) was released in December 2016.

This new version has an API-centric architecture with functionalities 'off-loaded' to modular components, leaving the API at the core. This makes World Wind itself a plugin, so that it can be used as interchangeably as possible (for example via Python). This refactoring exercise allows World Wind to be accessed via a browser as a Java Applet. A preview of the World Wind Java SDK^[10] was released on May 11, 2007 during Sun Microsystem's annual JavaOne conference.

Since WWj is an SDK, there is no single application; instead there are any number of applications using WWj, each with different functionalities, created by government agencies and commercial developers from around the world. These applications include simple virtual globe viewers, satellite tracker, GIS platforms, photo editor, F-16 simulator, mission planning software and many more.

Tutorials

• NASA World Wind SDK Tutorial: This Tutorial was developed by the Institute for Geoinformatics from the University of Münster, Germany. It contains tutorials from setting up an Eclipse environment with the World Wind API to building polygons from Linked Open Data geographic datasets. It contains important tips from beginners to advanced developers.

Forks and clones

• Geoforge project^[11] contains a fork of the NASA World Wind project. Geoforge provides open source software. It leads in a platform^[12] that manages geosciences data and uses WorldWind features to provide a display of geo-localised geosciences objects.
• Dapple^[13] is a fork of the NASA World Wind project, it is an Open Source project created by developers at Geosoft. Dapple is aimed at geoscience professionals, and has features aimed at them, such as easy addition of WMS servers and a simpler UI very similar to Google Earth's.
• SERVIR-VIZ^[14] is a customized version of World Wind developed by IAGT for the SERVIR project.
• WW2D was a cross-platform, free and open-source application based on Java and OpenGL technologies and can be run on Microsoft Windows, Mac OS X, Linux (x86 and x86-64) and Solaris on SPARC. WW2D uses images from World Wind's servers.
  • WW2D Plus One - an update to WW2D providing a 3D view.
• Punt was a fork of the NASA World Wind project, and was started by two members of the free software community who had made contributions to World Wind. Punt was based on the code in World Wind 1.3.2, but its initial release has features not found in World Wind 1.3.2 or 1.3.3 (such as support for multiple languages). Currently, Punt is only available for Windows, but long-term goals include a desire to move to a cross-platform solution.

Datasets available

Low resolution Blue Marble datasets are included with the initial download; as a user zooms into certain areas, additional high resolution data is downloaded from the NASA servers. The size of all currently available data sets is about 4.6 terabytes.

Earth

Animated data layers

• Scientific Visualization Studio
• MODIS
• GLOBE^[15]
• NRL Real-Time Weather

Image/terrain datasets

• Blue Marble Next Generation imagery
• Landsat 7 imagery
  • NLT Landsat (Visible & Pseudo Color)
  • Geocover 1990 & 2000 (pseudo; 1990 layer was produced from Landsat 4 & 5 images)
  • OnEarth (visible & pseudo)
  • i-cubed (visible)
• USGS imagery
  • Digital Ortho (DOQ - scanned black and white aerial image)s^[16]
  • Urban Area Ortho (montaged color aerial photography of many major US metropolitan areas)
  • Topographic maps
• Zoomit! imagery (community produced layer)
  • LINZ^[17] (montaged color aerial photography of New Zealand)
  • GSWA^[18] (Topographic and geological maps of Western Australia)
  • South Africa (colour satellite and aerial imagery)
  • US imagery (montaged color aerial photography of many major US metropolitan areas)
• SRTM (SRTM30Plus^[19]/SRTMv2/USGS NED) terrain data (includes bathymetry)

Extraterrestrial datasets

Moon

• Clementine (40xx - Colour, 30xx - Greyscale)
• Hypsometric Map

Mars

• MOC (Mars Global Surveyor - Mars Orbiter Camera)
• MOLA (MGS - Mars Orbiter Laser Altimeter hypsometric map)
• THEMIS (Mars Odyssey - Thermal Emission Imaging System)
• MDIM (Viking - Mars Digital Image Model)

Venus

• Magellan Imaging Radar (Color/Greyscale)
• Hypsometric Map

Jupiter

• Jupiter
• Callisto
• Europa
• Ganymede
• Io

Sloan Digital Sky Survey

Survey Imagery

• SDSS Server
• WMAP Image Server

Footprint Imagery

• SDSS Footprint
• FIRST (Faint Images of the Radio Sky at Twenty-cm)^[20] Footprint

Specifications

Baseline resolutions

• 500 m (Blue Marble Next Generation)
• 15 m (Landsat imagery; except for polar areas)

Typical high resolutions

• U.S.
  • USGS Digital Ortho: 1 m (grayscale; near full coverage)
  • USGS Urban Area Ortho: 0.25 m^[21]
  • Zoomit!: 0.15 m to 1 m^[22]
• New Zealand
  • Zoomit! (from LINZ data): 2.5 m (colour and grayscale)
• Western Australia
  • Zoomit! (from GSWA): 250K surface geology mosaic, 250K topographic data, Magnetic Intensity, Bouger Gravity
• South Africa
  • Zoomit!: Spot5 10m^[23] (colour near full coverage), Robben Island 0.5 m, Johannesburg 2.5 m

Altitude resolution

• U.S.: 30 m (1 arcsecond; USGS NED)
• Global: 90 m (3 arcseconds; SRTM)
• Oceans: 2 arcminutes and better

Age

• Some USGS aerial images were taken in the early 1990s.
• Landsat 7 images are all taken after 1999 (except for Geocover 1990).

See also

References

External links

Media related to NASA World Wind at Wikimedia Commons

• Official website
• NASA World Wind Java
• NASA World Wind.NET (legacy) at SourceForge