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Satellites for Everyone

clearcuts.jpgWe've been talking about the proliferation of satellite images for public consumption here at WorldChanging for awhile now, but Google's recent integration of their mapping application and the recently-acquired Keyhole satellite data has brought the topic back into the limelight.

Most evocative are the "memory maps" which use the system's ability to add pointers and links to the satellite maps. Creators of the memory maps annotate the images, describing their own histories and lives, illustrating them with the photos from space. The memory maps are then posted to the image site Flickr; the memory map category has (as of this evening) 379 photos. The annotation feature is part of Flickr, not the Google maps, but one can easily imagine Google adding it -- being able to share comments and observations along with map URLs is quite useful.

But people aren't just using the Google satellite maps for nostalgia.

David Shea's weblog Mezzoblue has grabbed satellite images of clear-cut forest outside of Kamloops, Canada. The pictures are both beautiful and devastating, and say more about clear-cut forestry in four photos than one could say with pages of text. There's something about the impersonal feel of satellite images that makes them somehow especially powerful as chronicles of events. Photos of these clear-cut areas taken from the ground or even from an aircraft overhead would no doubt be compelling, but the viewer would still be aware of the choices made by the photographer -- the angle, the lighting, the composition. Satellite images are stark and devoid of art -- they simply show what they see from hundreds of miles up.

Satellite images are a terrific tool for environmentalists, possibly one of the best in the toolkit. We have grown accustomed to the conventions of satellite photos, and most people in media-saturated parts of the world will grasp what they're seeing relatively quickly. If mobile phones and digital cameras are tools for recording what is seen in specific places and times, satellite images provide context and scope. The Mezzoblue series of pictures does that spectacularly well, but we can also see it in the use of satellite photos for tracking wildlife, revealing the extent of natural disasters, even tracking the pace of urban growth.

This is "open source intelligence," a term which referred originally to the use of open (i.e., publicly available) sources for information, but also increasingly refers to the use of readily shared material. Right now, open source intelligence is generally considered the realm of NGOs focusing on military and conventional political issues. Increasingly, we'll see it become a regular part of how activists -- particularly environmental activists -- document their focal issues.

There are, for now, two problems with the use of satellite images for activism. One is the lag -- satellite images are by no means live shots, and only will show what was seen the last time the satellite got a clear picture of the location. The satellite photo could be months, even years old. The number of accessible imaging satellites is growing, and if Keyhole doesn't have a recent shot, check out Terraserver (easily used through the Acme Mapper interface). Nonetheless, unless one gets lucky, satellite photos are likely to be of little use for documenting events which pass quickly. The other problem is equally significant. As of now, Google maps only provides detailed service to North America -- the US and parts of Canada -- and Terraserver is US-only for its free content. If you want to document something happening in New Jersey or New Mexico, no problem; if you want to document something happening on Jersey Island or in Mexico City, you may be out of luck.

Although cameras suitable for taking pictures from orbit are getting better, smaller and cheaper, launching a satellite remains an expensive proposition. We're not likely to see the era of personal sats for awhile yet, and it will probably require the construction of an orbital elevator. Still, that doesn't mean that the satellite images we do have available are without their use. Even if we can't use them to document every passing incident, many of the problems needing solutions are long-term, persistent issues. I anticipate seeing websites documenting environmental and social problems using Google Satellite Maps at any moment.

Comments (1)

".....the viewer would still be aware of the choices made by the photographer -- the angle, the lighting, the composition. Satellite images are stark and devoid of art -- they simply show what they see from hundreds of miles up"

-- well not really. What you see in most of these images is a technician's translation of enormous volumes of data into a true color rendering of the landscape. Depending on the sensor on the satellite, any given pixel may contain data gathered from points all over the electromagnetic spectrum. Imaging software allows you to "view" these data in a variety of ways. You might look at the thermal bands to detect variations in surface temperature; or you might use the values from infra-red end of the spectrum to measure vegetation.

The images you see on Google and other popular sites are the eye candy products. They're the tip of the data iceberg. We've barely begun to "see" all the patterns and information that will become available from these sensors and to find applications for them.......


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