Title of Paper: XML as a MultiMedia Window into Science Data

Principal Author: Don Brown

Abstract: We are prototyping an XML based system to provide metadata services that mirror data services such as subsetting that are used to derive new products from HDF-EOS source products. The HDF-EOS API provides services on the data without providing corresponding services on all EOSDIS meta-data, which can result in new data products with invalid meta-data. This project focuses on the impacts that XML and related technologies can have on creating data product with consistent data and meta-data. . We are addressing issues around the use of metadata in EOSDIS and larger Earth Science community and with the location of metadata in the HDF-EOS file itself. To focus the effort, data was selected from MODIS and MISR based on diverse subsetting criteria. Subsetting of data and the corresponding metadata has been used as the catalyst for identifying the issues that are pertinent to other services and data types. Our approach uses XML and XSL as tools to aid in configuring a framework that calls external applications to actually derive the new metadata values. An attempt to utilize existing subset tools and access data via the HDF-EOS and HDF APIs has made simultaneous services on data and metadata impossible at this juncture. Our approach, therefore, is to provide a tool to augment existing sub-setters by updating the new data products with consistent meta-data. Conclusions reached so far range on issues from the usability of XML Schema to impacts of the HDF-EOS metadata model on the ability to provide services to both data and metadata from the Terra project. Conclusions carry implications for future metadata models and the use of XML and related technologies for providing services for HDF-EOS data.