NASA STANDARDS FOR EARTH REMOTE SENSING DATA

Earth Observing System (EOS) is one of NASA's large programs for Earth science and global change research. In order to process, distribute, and archive data from EOS satellites and to facilitate interdisciplinary research, NASA has developed the EOS Data and Information System (EOSDIS) that defines a set of standards to deal with remote sensing data. In EOSDIS, data are grouped into three conceptual data models: grid, swath, and point. Each model defines the data object, the components of the object, and the relationship among the components. The EOSDIS conceptual data models are implemented in HDF by mapping the conceptual models into HDF internal data structures. The implementation of the conceptual data models in HDF is called HDF-EOS. In addition, EOSDIS has also developed metadata standards. There are two types of metadata in EOSDIS: structure and product. The structure metadata define the relationship among data components of a data model while the product metadata describe the data product. Both product and structure metadata are encoded in text format by using Object Description Language (ODL) and stored as attributes in HDF-EOS files. NASA provides HDF-EOS libraries for creating and accessing HDF-EOS files. In order to broaden the use of EOS data and facilitate data interoperability, NASA has actively participated in the development of remote sensing data standards through U.S. Federal Geographic Data Committee (FGDC), ISO Technical Committee 211, and Open GIS Consortium (OGC). Currently NASA is leading the development of several remote sensing data standards for those standardization organizations.