9/24/2023 0 Comments Nasa world wind google earth![]() With tools such as WMS and MODIS built in, World Wind allows viewing of recent world events, weather patterns, fires, and any other imagery people have desired to make available. World Wind is an education tool that allows users to explore many aspects of the Earth and Moon. NASA World Wind is available free of charge. Additional components for the $400 per year version cost $200 each. These versions start at $20 a year and quickly jump to $400 a year, with the Enterprise versions requiring contact from a sales person. Web site and all contents © Copyright TERRAINMAP Earth Imaging LLC 2010, 2011, All rights reserved.As well as the free version (which can display small ads), there are additional versions of Google Earth available with different features. The results are shown below.Īlthough not designed as a data source, the NASA WorldWind SDK demonstration applet can provide useful data for many applications. I draped the satellite image over the flipped DEM using the free 3DEM utility. The satellite image is also shown (this does not have to be flipped): The raw and flipped DEM renderings are shown below. The file will be saved as a GeoTiff DEM (not a raster image).Īs an example of how to build a terrain model, I downloaded a mountainous scene in central Tibet. You can save the file by selecting 'File' | 'Save Grayscale Image' | 'GeoTiff'. A rendering of the processed file will appear. Then select 'DisplayOne File' | 'Display GeoTiff IEEE FP 32 Elevation Image' | 'Flipped'. To produce a corrected file, select 'File' | 'Open' and open the elevation file. It is necessary to flip the elevation postings without changing the georeferencing in order to use the data. ![]() The elevation data is saved by NASA in GeoTiff format using IEEE floating point 32 bit representation for the elevation postings. PANCROMA has a utility for correcting this problem. ![]() These can be used by other applications like the excellent 3DEM for preparing terrain models by draping the image over the elevation model.Īs mentioned, an issue with this data is that the elevation files are saved mirror flipped around the center latitude line. An example USGS NAIP image dowloaded from WorldWind is shown below.Īfter selecting your area of interest, you can save both the image file and the elevation files separately. As far as I can tell, the Urban Ortho Image layer and the USGS topographic map data layers have not been implemented in the demonstration applet. The USDA NAIP and USGS NAIP USGS data layers seem to have the highest resolution, apparently around 2m. Note that only the first four data layers are relevant for areas outside of the United States. I found that checking the following layers was helpful: You will need to check some of the relevant data layers in order to best navigate the virtual globe. There is a slight glitch to doing this as the elevation files are downloaded mirror flipped over the central East-West latitude line, but PANCROMA has a utility to correct this.Īfter navigating to the Demo Applications page, scroll down to the 'Exporting Surface Imagery and Elevations' utility. This greatly facilitates draping the image over the DEM to create terrain models. Using this program, it is possible to download co-registered satellite imagery along with SRTM DEM data. This article examines one of them, the 'Exporting Surface Imagery and Elevations' utility. ![]() Some of these are very interesting and useful. NASA posts demonstration Java applets at its Java SDK site. NASA also released the WorldWind SDK, an API designed to let developers access and extend the core capabilities. Unlike Google Earth, WorldWind is an open source application, and has been quietly adding capabilities, thanks in large part to its connection with NASA and its access to their data. WorldWind appeared around 2004 (about the same time as Google Earth) but was overshadowed into near obscurity by the massive marketing power of Google. Many GIS users are familiar with the NASA WorldWind virtual globe utility as the less well-known cousin of the extremely popular Google Earth application. See additional satellite image processing articles at menu selection 'White Papers' ![]()
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