Earth Observation

Remote sensing satellites collect images of the earth by using various methods, including electro-optical sensors and radar. Electro-optical sensors may collect images by using one light frequency (panchromatic) or several frequencies (multispectral) or may collect images contiguously over a broad range of frequencies (hyperspectral). Radar satellites bounce radar signals off the earth's surface and record the energy that is returned. Radar imagery can be used to "see" through clouds and collect images in the daytime or at night. The sharpness and detail of photographs can be related to a satellite sensor's resolution, which usually is measured in meters.

Over the last several years, a number of commercial firms have contracted with foreign government agencies that sell data from remote sensing satellites in the international marketplace. Simultaneously, a number of U.S. firms have begun to develop commercial private systems that would distribute their own data to the commercial market. This has initiated a fierce competition between satellite operators-owners and data distributors that should drive down the price of imagery.

Under the U.S. policy allowing high-resolution satellites to market data commercially, the U.S. industry is leading the world in the development of these high-resolution remote sensing satellites. Three U.S. companies are developing high-resolution (less than 1-meter) satellites that should be in operation by the end of the decade. These satellites will compete directly with aerial photography for the high-resolution imagery market. Satellites offering pictures of the earth that have the same clarity as aerial photographs will compete in terms of price and the timeliness of the images. While no other commercial providers have developed 1-meter resolution systems, the market demand that evolves will deter-mine how many systems with that level of detail are needed in the marketplace and whether the data can be made available at a reasonable cost.