WC Archive

Although systems like Google Earth aren't "real time" (that is, they don't present live data, but images captured over recent months or sometimes years), the use of standardized languages for the display of information allows for the combination of satellite maps with pictures from aircraft or from other satellites. The value of such a combination became evident in the response to the late 2005 disasters of Hurricane Katrina and the Pakistan earthquake.

This technique of overlaying images found an unexpected application when Hurricane Katrina flooded New Orleans and the surrounding areas on 29 August 2005. The National Oceanic and Atmospheric Administration (NOAA) captured more than 8,000 images of flood-damaged areas over 10 days using a high-resolution camera mounted on a small high-speed aircraft. This information was invaluable to rescue efforts, and in the first week some 5 million photos were downloaded from NOAA's website each day.

But navigating this huge, unprocessed data set in a meaningful way required the images to be presented in a searchable, stitched-together format. At the request of NOAA, Google Earth and the Global Connection team created new KML software tools to handle the images that NOAA released on a daily basis. These tools made the preparation of image overlays faster than was previously possible. During September, we estimated that the Global Connection server supported some 2.5 million viewings of the high-resolution overlays of post-Katrina images by users of Google Earth.

[...] Unlike the situation after Katrina, there was no high-speed aircraft surveying the disaster area in Pakistan nor high-resolution images available, apart from commercial satellite data. But by 14 October, Google Earth had acquired, processed and published two satellite images from Digital Globe's QuickBird that were taken on 9 October, the day after the earthquake. In the five days that followed, high-resolution images taken by the commercial IKONOS satellite were released publicly on several websites, then withdrawn following Pakistan's concerns over security in Kashmir, and finally re-published by the United Nations following talks with Pakistan and India.

Unsurprisingly, Declan Butler -- who created the H5N1 avian flu mashup for Google Earth -- wrote one of the big picture articles in the February 16 Nature. (Butler gives a bit of background to the story on his own blog.) Butler's piece describes various ways in which the geographic information displayed on these virtual globes has particular scientific value. In short, the importance of digital maps is that they allow a visually meaningful rendition of otherwise hard-to-see patterns. The human brain is particularly good at identifying patterns in visual information (as anyone who has seen pictures in clouds or matched up the Wizard of Oz with the Dark Side of the Moon can attest); correlations hidden in spreadsheets and text can leap off the screen when shown on a map. Although geographic information systems have been used by scientists for years, the advantage of a system like Google Earth (or NASA's World Wind) is the ease with which new data overlays can be constructed. Just like digital movie making tools opened up a new creative arena for budget and time-limited filmmakers, systems like Google Earth have opened up new information display possibilities for scientists otherwise too occupied with their work to learn the intricacies of "real" GIS software.

As cool as Google Earth is, new applications coming down the road may prove to be even more worldchanging. ESRI, makers of the widely-used GIS application ArcView, has a new version in the works that combines the visuals of Google Earth with an open format:

Data in Google Earth need to be in a specific format; ESRI's tool will allow users to view not only data from ESRI's own products, but also information in formats that are being increasingly standardized through the Open Geospatial Consortium. This international body is working to ensure that computers can understand descriptions of the spatial features of anything from highways and postcodes to icebergs.

The next phase of this revolution will come when everyday people can contribute images to the online map that add better-than-satellite resolution to the content. WikiGlobe, we await your arrival!