A constellation of satellites that routinely and frequently images the Earth's land surface in consistently
calibrated wavelengths from the visible through the microwave and in spatial detail that ranges from submeter
to hundreds of meters would offer enormous potential benefits to society. A well-designed and
effectively operated land surface imaging satellite constellation could have great positive impact not only on
the quality of life for citizens of all nations, but also on mankind's very ability to sustain life as we know it on
this planet long into the future.
The primary objective of the Committee on Earth Observation Satellites (CEOS) Land Surface Imaging (LSI)
Constellation is to define standards (or guidelines) that describe optimal future
LSI Constellation capabilities,
characteristics, and practices. Standards defined for a LSI Constellation will be based on a thorough
understanding of user requirements, and they will address at least three fundamental areas of the systems
comprising a Land Surface Imaging Constellation: the space segments, the ground segments, and relevant
policies and plans. Studies conducted by the LSI Constellation Study Team also will address current and
shorter-term problems and issues facing the land remote sensing community today, such as seeking ways to
work more cooperatively in the operation of existing land surface imaging systems and helping to accomplish
tangible benefits to society through application of land surface image data acquired by existing systems.
2007 LSI Constellation studies are designed to establish initial international agreements, develop preliminary
standards for a mid-resolution land surface imaging constellation, and contribute data to a global forest
The primary objective of the Earth Resources Observation System (EROS) Data Center (EDC) Distributed Active Archive Center (DAAC) for land processes data is to promote the interdisciplinary study and understanding of the integrated Earth system by providing remotely sensed and related ancillary data for the study, characterization, and monitoring of natural and anthropogenic conditions and processes existing and operating at or near the land surface. Generating, distributing, and preserving data and products from the National Aeronautics and Space Administration's (NASA) earth observing system (EOS) are primary functions of the DAAC. To that end, the EDC DAAC is using existing data sets in developing capabilities to efficiently and effectively ingest, process, manage, distribute, and archive for future generations land-related data collected by EOS sensors. Capabilities also are being developed to help users search for and acquire data and products, as well as to support their scientific application of those data and products. EDC DAAC programs and capability development activities address DAAC-defined science support requirements that relate to a broad spectrum of services and capabilities needed by science users.
In addition to acquiring multispectral data, the advanced spaceborne thermal emission and reflectance radiometer (ASTER) will also acquire along-track stereo data. ASTER is capable of acquiring 771 digital stereo pairs per day, each covering 60 by 60 km on the ground, at 15 m resolution with a base/height ratio of 0.6. According to present plans, approximately 30 digital elevation models (DEMs), with 7 - 50 m accuracy (RMSExyz) will be produced daily. During the 5 year mission on the EOS AM1 platform, ASTER has the potential to provide a coherent digital stereo dataset covering the Earth's land surface. At minimum, DEMs derived from these data will augment topographic data from other sources. These fundamental geophysical measurements will be a major contribution to interdisciplinary studies of the Earth as a planet.