Wanted: Better Broad-Area Imagery
While the commercial high-resolution satellite imagery that has become available in recent years is being fully integrated into U.S. military operations, this has not diminished the need for the broad-area coverage traditionally provided by the U.S. Landsat and French Spot satellite systems, according to Pentagon officials.
But these officials also say current broad-area satellite coverage leaves much to be desired in terms of image resolution and availability. The U.S. military sorely needs a system comparable to RapidEye, a German-led commercial program to deploy a five-satellite constellation for collecting medium-resolution imagery, these officials said.
The officials expressed concern with the current White House strategy for replacing its existing Landsat 5 and Landsat 7 satellites. Landsat 5 is more than 20 years old and has no data-recording capability, while Landsat 7 is returning fractured imagery scenes due to a main sensor glitch that U.S. government officials say cannot be fixed.
The White House replacement plan, which calls for incorporating a Landsat-type sensor on a new generation of civil-military weather satellites slated to begin launching around the end of the decade, would squander an opportunity to make a big leap forward in capability, the military officials said. They acknowledged that their cause has yet to find an advocate in the top ranks of the Pentagon.
The White House might be rethinking its Landsat replacement strategy following recommendations in late September by NASA and the U.S. Geological Survey — the agencies that administer the Landsat program — to fly a dedicated satellite rather than piggyback on the weather satellite program. White House officials are reviewing that proposal, according to government and industry sources.
A better idea, the military officials said, would be to buy and launch a constellation similar to the RapidEye system. RapidEye AG of Brandenburg, Germany, plans to launch its five-satellite system in 2007. Each of the satellites will carry a multispectral, or color, sensor with 6.5-meter imaging resolution and a swath width of 77 kilometers.
In terms of resolution and swath-width capabilities, RapidEye falls in between Landsat and the U.S. commercial imaging satellites now in operation. The Landsat 7 satellite has a swath width of 180 kilometers and offers resolutions of 15 meters in panchromatic, or black and white, mode and 30 meters in multispectral mode. The commercial satellites offer higher resolution, about 1 meter in panchromatic mode and 4 meters or sharper in color, but their swath widths are in all cases less than 20 kilometers.
In addition, with five satellites, the RapidEye system would be able to revisit areas of interest with much greater frequency than the other systems.
If the U.S. government were to buy its own five-satellite constellation it could operate in tandem with the RapidEye system for even better revisit times, the military officials said. And by owning and managing system, the government would have guaranteed access to medium-resolution, broad-area imagery regardless of political circumstances, they said.
Officials with RapidEye AG say their business plan primarily targets the global insurance and agriculture markets, but military applications abound for the system, according to one Pentagon source. Data from a RapidEye-type system will be useful in reconnaissance and for precision mission planning and rehearsal, the official said. It also could be used for strategic purposes, such as monitoring crop yields in places like North Korea.
Medium-resolution, broad-area imagery from unclassified sources is easy to share with other governments and nongovernment agencies working in disaster relief efforts, this official said. That also has a strategic benefit in that the more help the United States can offer in such efforts, the more goodwill it engenders abroad, the official said.