The SDP Toolkit provides the interface between EOS science data production software and the remainder of the Science Data Production System. It allows portability of science software across approved computing platforms at the DAACs and also across the Science Computing Facility development environments and the DAACs. A goal of the Toolkit is reduced integration expense at the DAAC and enhanced maintainability of software.
SCF version: The SCF version of the Toolkit is specifically tailored for use at Science Computing Facilities. The Toolkit API (library calls from science software) will not change in the DAAC environment.
MTD version: The MTD Toolkit is a subset of SCF Toolkit, providing tools for Metadata handling and Time/Date conversion. The primary purpose of this tool set is to allow EOSDIS extended data providers the capability of formatting their products in ECS standard formats, without requiring the entire SDP Toolkit package. Toolkit_MTD will also allow creation of and access to ECS standard metadata. Toolkit_MTD is intended to be used by data providers who will produce products at their local facilities and then deliver those products to be archived and distributed from ECS Data Active Archive Centers (DAACs). The tools are not intended to be used by ECS instrument teams who will deliver production code to the DAACs. For this reason, the metadata and time conversion tools have been extracted from the rest of the Toolkit, giving a streamlined version for use by external (to ECS) data providers.
The Hierarchical Data Format (HDF) is a data format designed to facilitate sharing of scientific data in a heterogeneous computing environment. Features include platform independence, user extendibility, and embedded metadata such as units, labels, and other descriptors. The data may reside in any of five data types: multidimensional array, text, table, raster image, and palette. Both C and FORTRAN functions are available to access and process the data. HDF was developed by The HDF Group (THG).
HDF-EOS is standard HDF with ECS conventions and metadata added. The principal distinction is the specification of three geolocation data types: point, grid, and swath, which allow the file contents to be queried by earth coordinates and time. An HDF-EOS file also contains ECS core metadata which is essential for ECS search services. An HDF-EOS file can be read by any tool that processes standard HDF files. However, it will be difficult for a standard HDF call to interpret HDF-EOS geolocation or temporal information without further knowledge of the file structure. A data product need not fit any of the grid, point or swath models to be considered HDF-EOS. As long as ECS metadata are included, it will be a valid HDF-EOS file.
