Abstract:
NASA’s Earth Observing System Data and Information System (EOSDIS) provides a wealth of data and products supporting scientific research of the atmosphere, oceans, and land. Data from the Earth Observing System (EOS) instruments onboard the Terra, Aqua, and Aura satellites make global measurements daily. The measurements are processed into higher-level “standard” products within 8–40 hours of
... observation and then made available to users, primarily Earth science researchers. However, application users, operational agencies, and even researchers desire EOS products to support research and applications, such as numerical weather and climate prediction; forecasting and monitoring natural hazards, ecological/invasive species, agriculture, and air quality; providing help with disaster relief; and homeland security. These users often need data much sooner than routine science processing allows, usually within three hours, and are willing to trade science product quality for timely access. In response to this need, NASA has developed a new Land Atmosphere Near Real-time Capability for EOS (LANCE).
Building on the existing EOSDIS near real-time (NRT) capabilities, NASA’s Earth Science Division sponsored the development of LANCE. LANCE consists of special processing elements, co-located with selected EOSDIS data centers and processing facilities. These elements process expedited data from the EOS Data and Operations System (EDOS) using optimized science algorithms to provide data in near real-time. The LANCE system development is jointly sponsored by the Flight, Research and Analysis, and Applied Sciences Programs within NASA’s ESD.
The LANCE architecture leverages existing near real-time satellite data processing systems that are managed by the Earth Science Data and Information System (ESDIS) Project at Goddard Space Flight Center (GSFC). Near real-time data are currently available for MODIS, the Ozone Monitoring Instrument (OMI), the Atmospheric Infrared Sounder (AIRS), and the Microwave Limb Sounder (MLS) instruments. Implementation of the Advanced Microwave Scanning Radiometer – Earth Observing System (AMSR-E) near real-time system is under development. The diagram on the left/right shows the three LANCE elements at the GSFC Earth Sciences Data and Information Services Center (GES DISC), the OMI Science Investigator-led Processing System (SIPS), and the MODIS Adaptive Processing System (MODAPS). These elements are supplied with rate-buffered data and/or session-based production datasets from the EDOS as soon as they are downlinked from satellites or transmitted from ground stations, generally within 30 minutes to two hours after observation. Each element then processes raw data into higher-level products before they are made available to users. A key NASA tenet, that of product validation and documentation by science instrument team members is being applied here as well as to the standard products, to ensure that user feedback and evolving user needs will translate into appropriate product modifications and new products.
Building on a significant investment by NASA in developing algorithms and products, LANCE provides a range of products that have demonstrated utility for applications requiring near real-time data. From lower level data products such as calibrated geolocated radiances to higher-level products such as sea ice extent, snow cover, and cloud cover, users have integrated LANCE data into forecast models and decision support systems.
[Summary provided by NASA.] 
