Technology challenges for Earth observation from higher orbits

Advances in Earth observing technologies are required to fulfill NASA's long-term vision for Earth system prediction in the years 2010 to 2020. The observing system during these years will include satellites in a variety of orbits including smaller, smarter ones in low Earth orbit, large aperture sensors in medium Earth orbit and geostationary orbit to provide enhanced temporal coverage and perhaps sentinel satellites at Lagrange points L1 and L2 to provide synoptic views of the entire globe. These higher vistas can meet pending science challenges in a variety of areas directly relevant to NASA’s plans. They include, among others, meeting high temporal and spatial resolutions to observe rapidly evolving chemical events in the global atmosphere, meeting the requirements of increased spatial and temporal sensing of varying precipitation events over portions of the globe, and the increased temporal coverage necessary to see clear skies over coastal regions for coastal process monitoring. A set of technology tradeoffs and needs that meet the above science challenges can be identified. They include an increase in collecting aperture for passive measurements, increased transmitted power for active measurements, and improved on-board processing coupled with enhanced bandwidth communications as data collection increases. The technologies will involve differentiating filled versus sparse aperture collection systems, developing advanced scanning capabilities and large array detectors, as well as large structure pointing control and metrology. This talk will examine these issues for a range of NASA Earth science measurements.