Facilitating Accessibility and Exploitation of Historic AVHRR Products

Abstract

The German Satellite Data Archive (D-SDA) provides data archiving and access services in the context of space-borne Earth observation mission and ensures long-term data preservation (LTDP) of the payload data and derived spatial information products. The archived data are accessible to a variety of users and communities via established, largely automated ordering processes including online data delivery. To keep pace with technological progress, D-SDA also develops and applies new technologies and tools for facilitating data access and use, with options for directly analyzing Earth observation data without the need to download products or to deploy specialized software. The EOC Geoservice is the spatial data infrastructure of the DLR Earth Observation Center (EOC). The EOC Geoservice provides interoperable spatial data services for efficient data discovery, visualization, and direct download based on the standards set by the Open Geospatial Consortium (OGC). A selection of historic and current geospatial data hosted by the D-SDA have been integrated into the EOC Geoservice with more data being added continuously. These state-of-the-art services facilitate data interoperability and exploitation. D-SDA has been archiving the data of the Advanced Very High Resolution Radiometer (AVHRR) on board of the National Oceanic and Atmospheric Administration’s (NOAA) fleet of Polar Operational Environmental Satellites (POES) since 1983. For three decades DLR has been generating and archiving regional coverages of daily AVHRR level 3 products – vegetation index, sea surface temperature and land surface temperature. D-SDA is now making a subset of its AVHRR level 3 data archive available via geospatial web services provided by the EOC Geoservice. This will demonstrate the value of online data services to facilitate exploitation of valuable time series of data otherwise ‘buried’ deep in a preservation infrastructure. Additionally, integrating these data into the EOC Geoservice infrastructure serves as a prototype for the DLR ’TIMELINE’ project. As a ‘mission to archive’ TIMELINE will consolidate and re-process the entire D-SDA AVHRR data holdings into a range of AVHRR level 3 products. In the future these products will also be made available via the EOC Geoservice geospatial web services. Integrating more and more of its historic data into spatial data services, D-SDA is building a bridge between preservation and value adding. Combined with open data policies, it simplifies exploitation and trend analysis and makes valuable Earth observations accessible to researchers and non-expert users alike.