>> Valley glaciers appear as fingers of blue ice reaching out from the Vatnajökull Glacier in Iceland’s Skaftafell National Park. The park lies on the southern edge of Vatnajökull, Europe’s largest ice cap. Landsat 7 image captured August 4, 1999, courtesy of USGS and NASA.
The 1992 law made private sector ownership and operation of remote sensing systems more commercially attractive. Now three U.S. companies operate highly capable, high resolution commercial systems. The three competitors will soon reduce to two when OrbImage completes its buyout of Space Imaging. The combined company will then compete for market share only with Digital Globe. The U.S. high resolution industry, if not yet robust, is now growing in size and global reach. With U.S. policy and companies in the lead, the rest of the world is moving into orbit with a wide variety of spacecraft.
Meanwhile, U.S. policy towards Landsat data continuity falters. Data continuity is required by Public Law 102-555 because it is important for the many applications of Landsat data to federal and state agency needs. Nevertheless, it is continually at risk from infighting among the various federal agencies that use the data. Basically, they all want the data, but only if another agency pays for the system. Because the Landsat series serves a varied set of users in both the scientific and applied communities, it has never had a strong agency champion.
Even though its scientists make extensive use of Landsat data, NASA does not want to continue building and launching Landsat satellites. It would like to move on to more challenging engineering and scientific projects. However, without major changes in their budgets and focus, neither NOAA nor USGS can support such a project. As agencies within much larger departments, they also have a difficult time justifying a large budget increase. The Department of Defense (DOD), which yearly uses thousands of landsat scenes, is not willing to pay for the system either.
After many false starts and delays, there is now a plan that would place a Landsattype Operational Land Imager (OLI) on the NPOESS satellites. These are the new, improved meteorological satellites developed by NOAA, NASA, and DOD. However, the first of the NPOESS birds is now scheduled for launch only in 2010 (http://ldcm.usgs.gov). Thus there will likely be a significant Landsat data gap, as the only Landsat satellites now operating are the damaged Landsat 7 and, amazingly, Landsat 5, which was launched in 1984.
The NPOESS satellites will fly in a different orbit from Landsat 7, yielding a smaller scene size (177 km, versus 185 km) and different scene center line. The OLI, which is not yet designed, would maintain the same 30-meter multispectral and 15-meter panchromatic resolutions and contain three additional spectral bands compared to Landsat (one blue and two short wavelength infrared). Unlike Landsat 7, it would not carry a thermal band. It is not clear that data users will find such changes immediately workable, since even relatively small changes in the data characteristics may require significant changes in their applications algorithms. Users of the thermal band are simply out of luck in the OLI era.
Still to be worked out is the funding for the sensor, additional ground systems, and operations costs, which could further delay the system. In other words, do not expect to see the impending data gap filled any time soon.