Best Practices for International Collaboration and Applications of Interoperability within a NASA Data Center

The Physical Oceanographic Distributed Active Archive Center (PO.DAAC) is one of 12 data centers sponsored by NASA's Earth Science Data and Information System (ESDIS) project. The PO.DAAC is tasked with archival and distribution of NASA Earth science missions specific to physical oceanography, many of which have interdisciplinary applications for weather forecasting/monitoring, ocean biology, ocean modeling, and climate studies. PO.DAAC has a 20-year history of cross-project and international collaborations with partners in Europe, Japan, Australia, and the UK. Domestically, the PO.DAAC has successfully established lasting partners with non-NASA institutions and projects including the National Oceanic and Atmospheric Administration (NOAA), United States Navy, Remote Sensing Systems, and Unidata. A key component of these partnerships is PO.DAAC's direct involvement with international working groups and science teams, such as the Group for High Resolution Sea Surface Temperature (GHRSST), International Ocean Vector Winds Science Team (IOVWST), Ocean Surface Topography Science Team (OSTST), and the Committee on Earth Observing Satellites (CEOS). To help bolster new and existing collaborations, the PO.DAAC has established a standardized approach to its internal Data Management and Archiving System (DMAS), utilizing a Data Dictionary to provide the baseline standard for entry and capture of dataset and granule metadata. Furthermore, the PO.DAAC has established an end-to-end Dataset Lifecycle Policy, built upon both internal and external recommendations of best practices toward data stewardship. Together, DMAS, the Data Dictionary, and the Dataset Lifecycle Policy provide the infrastructure to enable standardized data and metadata to be fully ingested and harvested to facilitate interoperability and compatibility across data access protocols, tools, and services. The Dataset Lifecycle Policy provides the checks and balances to help ensure all incoming HDF and netCDF-based datasets meet minimum compliance requirements with the Lawrence Livermore National Laboratory's actively maintained Climate and Forecast (CF) conventions with additional goals toward metadata standards provided by the Attribute Convention for Dataset Discovery (ACDD), the International Organization for Standardization (ISO) 19100-series, and the Federal Geographic Data Committee (FGDC). By default, DMAS ensures all datasets are compliant with NASA's Global Change Master Directory (GCMD) and NASA's Reverb data discovery clearinghouse (also known as ECHO). For data access, PO.DAAC offers several widely-used technologies, including File Transfer Protocol (FTP), Open-source Project for a Network Data Access Protocol (OPeNDAP), and Thematic Realtime Environmental Distributed Data Services (THREDDS). These access technologies are available directly to users or through PO.DAAC's web interfaces, specifically the High-level Tool for Interactive Data Extraction (HiTIDE), Live Access Server (LAS), and PO.DAAC's set of search, image, and Consolidated Web Services (CWS). Lastly, PO.DAAC's newly introduced, standards-based CWS provide singular endpoints for search, imaging, and extraction capabilities, respectively, across L2/L3/L4 datasets. Altogether, these tools, services and policies serve to provide flexible, interoperable functionality for both users and data providers.