Thanks in part to an instrument created by MIT Lincoln Laboratory, NASA's Earth Observing-1 (EO-1) spacecraft is sending back stunningly detailed images of the planet.
Since its launch in November, EO-1, flying in formation with the Landsat 7 satellite, has taken more than 350 images. Comparing the images from Landsat 7 and EO-1 allows researchers to evaluate EO-1's land imaging instruments.
The primary instrument on EO-1 is the Advanced Land Imager (ALI), designed and developed at Lincoln Lab. One of three imaging instruments on board, ALI is the first Earth-observing instrument to be flown under NASA's New Millennium Program.
One of two new Earth-orbiting missions, EO-1's primary focus is to develop and test ALI and other advanced land imaging instruments. The goal is to demonstrate that a smaller, lighter, cheaper spacecraft can provide equal or better images than Landsat.
Uses for the new technology include land use studies, mineral resource assessment, coastal processes research and climate change studies. Images from Landsat have helped researchers understand, for instance, why Africa's freshwater Lake Chad has been disappearing over the last 30 years.
Scenes of Alaska taken by ALI in the panchromatic band are of considerably better quality than the panchromatic band image taken by Landsat 7 under nearly identical lighting and surface conditions. ALI, which uses novel wide-angle optics and a highly integrated multispectral and panchromatic spectrometer, provides more resolution, sensitivity and dynamic range than the comparable instrument on Landsat 7, NASA reports.
"A fully operational ALI may reduce the size and power requirements of future Landsat-type instruments by a factor of four to five," said Costas Digenis, associate leader of the Advanced Space and Concepts Group at Lincoln Lab and ALI program manager.
TESTING AND IMPROVING
Scientists and engineers at Lincoln Lab are evaluating the detailed technical performance of the ALI.
In parallel, a team of Earth scientists assembled by NASA is assessing the quality of the science products obtained and comparing results directly with those obtained from Landsat 7. These investigations will provide critical input for the design and implementation of the next generation Landsat imager.
The NASA Goddard Space Flight Center has overall responsibility for the EO-1 mission. Lincoln Lab developed ALI with New Millennium Program instrument team members Raytheon Santa Barbara Remote Sensing for the focal plane system and SSG, Inc. of Wilmington, MA for the optical system. Lincoln Lab was responsible for the design, fabrication and test of the instrument, as well as development of the software and databases for calibration, and is also responsible for the initial on-orbit performance assessment.
In 1996, NASA started the New Millennium Program to identify, develop and try out instrument and spacecraft technologies that may allow new or more cost-effective approaches to conducting science missions. Future NASA spacecraft are expected to be smaller, lighter and less expensive than current versions.
EO-1 is the first of three New Millennium Program Earth-orbiting missions. For more on EO-1, see http://eo1.gsfc.nasa.gov.
A version of this article appeared in MIT Tech Talk on March 14, 2001.