Joanna Glasner
said,
Critics of overhead imagery services like Google Earth and Microsoft Virtual Earth generally fall into two categories: government agencies who say the services show too much, and users who lament they can’t see more.
As the next generation of commercial imaging satellites moves closer to launch, the first camp may be out of luck.
Forthcoming features such as enhanced zoom capabilities, higher-resolution views and faster updates of stock imagery will reveal far more detail of Earth’s surface than anything visible on a computer screen today. While satellite imagery won’t be real-time, or capable of distinguishing individuals, it will be good enough to pinpoint ground-level details too blurry to identify using today’s technology.
“We’re just starting,” said Matthew M. O’Connell, CEO of GeoEye (formerly Orbimage), which plans to launch a satellite in early 2007 that can show images of objects as small as 1.3 feet across. “At that resolution, we can literally count the manhole covers in Manhattan.”
Just a few years ago, the idea of zooming in from a PC screen to any point on Earth would have seemed like the stuff of fantasy. Now that it’s reality, satellite and aerial mapping applications are drawing millions of addicted users. Hardly a week goes by without news of some strange or scandalous finding: Last week amateur astronomer Emilio González of Spain used Google Earth to find what might be a previously unknown impact crater in Chad.
Mapping programs rely on an amalgam of footage collected from satellites and airplanes, with the most detailed imagery — taken by aircraft — reserved for densely populated places.
However, much of that imagery is rather stale, with some footage dating back several years. That, too, is about to change. Collecting up-to-date imagery will become an easier task in the next two years, as satellites cover significantly wider swaths of territory on a daily basis.
GeoEye says its next-generation satellite, GeoEye-1, will be capable of acquiring each day approximately 270,000 square miles of imagery, an area about the size of Texas. That’s about seven times the area covered by Ikonos, the best imaging satellite the company has running today.
DigitalGlobe, the satellite imagery supplier for Google Earth, plans to launch its next orbital, WorldView 1, later this year. The company says it will be capable of collecting up to 193,000 square miles of imagery per day.
Next-generation satellites will also revisit locations more frequently.
Chuck Herring, spokesman for DigitalGlobe, anticipates that by combining WorldView and existing satellites, the firm will be able to revisit practically any point on Earth’s surface on a daily basis. (Currently, the company revisits about once every three days.)
Giving the planet a boost in refresh rate is an ambitious agenda — keeping up with urban sprawl has proven a losing proposition in the past.
In fast-growing regions like Phoenix, imagery even a few months old can look out-of-date. “Even Shanghai doesn’t have highly accurate maps,” said GeoEye’s O’Connell. “And in northern Virginia (where the company is based), it’s growing so rapidly that maps have to be updated constantly.”
Stephen Lawler, general manager of Microsoft’s Virtual Earth, plans to feed future iterations of the service more frequent flyover images of construction hot spots. But whatever he does, it’ll be hard to beat the dazzled expectations of novice users, who commonly believe they’re seeing a Stephensonian rendition of present-day reality.
“We get a lot of questions: Is that a real-time picture? Is that car really in my driveway right now?” said Lawler. “People are trying to understand.”
While public mapping sites are major consumers of satellite images, most demand still comes from governments and private industries for internal use.
Federal and local governments use imagery for everything from urban planning to drug enforcement. Although resolution is too low to make out individual plants, satellites can register reflected and emitted electromagnetic energy that can be matched (.pdf) with known drug crops.
In a similar vein, farmers use satellite imagery to track their crops. Environmental watchdogs use it to track oil spills, illegal dumping and other natural, man-made or pending disasters.
DigitalGlobe’s Herring says more uses of imagery will be discovered in years to come.
He’s optimistic about the prospects in light of the “Google Earth effect”: The more people view geo-spatial imagery, the more they incorporate it into how they visualize their surroundings.
“People are thinking in a geo-spatial way,” he said. “They’re not just thinking about where something is on the ground. When you look at a satellite image, you think of that area in a much different way.”
Microsoft’s Lawler envisions deeper integration occurring between online search and geo-spatial imaging. If the two mediums could be combined effectively, it could rectify what he sees as the key shortcoming of text-based search: the impossibility of finding something without the proper words to describe it.
Lawler used the example of recommending a restaurant to illustrate how imaging and search could work in tandem. In the hypothetical scenario, Lawler advised an out-of-town visitor to try a Thai restaurant near her hotel. But he could not remember the name or address, only that it had a blue awning.
Using current search technology, locating the restaurant would be a cumbersome task. With an imaging application, however, the visitor could click around on an aerial view of the area around her hotel and physically locate the restaurant.
“If I can recreate the real world with a digital representation,” Lawler said, “you can take out that fuzzy logic and find an answer.”
Mixing up search, imagery and mapping isn’t a new concept. Amazon.com’s A9 yellow pages contains snapshots and maps for businesses, searchable by name or location. Google’s local search feature also lets users look for locations and see results in a 3-D aerial view.
Higher-resolution satellite data will make better applications possible, said Sam Bacharach, director of outreach for the Open Geospatial Consortium. One he’d like to see is walking directions, which would require more detailed data than driving instructions.
But there are limits on the resolution of data that can be made public.
Currently, the federal government allows only satellite images at 1.6-foot resolution or coarser to be sold commercially, according to GeoEye.
Along with raising resolution, mapping sites are also experimenting with angles. Microsoft, in its attempt to compete against the wildly popular Google Earth, touts a feature showing images of urban areas taken at a 45-degree angle. This enables viewers to see the facades of homes and businesses in addition to roofs.
But for satellite imaging data, such details aren’t yet an option. O’Connell recalls delivering this disappointing news not long ago to a congressman, who wanted to know if it was possible to see prisoners in North Korean prisoner of war camps using satellites.
O’Connell replied: “Congressman, we’re flying overhead, so the best you’d see is the top of someone’s head.”
