D. Deng’s research while affiliated with George Mason University and other places

This Geospatial Web Service Client (GWSC) provides an interoperable way of accessing geospatial Web service, especially those from Open Geospatial Consortium (OGC), for integrating and analyzing distributed heterogeneous Earth science data. GWSC utilizes the geospatial interoperability and Web service standards developed by OGC, ISO, W3C, and GRID communities to enable in service discovery, invocation, negotiation, selection and composition. GWSC is in conformity with OGC Catalog Service for Web (CSW) specification to play a "directory" role that permits the registry, discovery and access of geospatial information resources that distribute on the Internet, such as services, data sets, data descriptions and their associations. By implementing the latest protocols of OGC Web Feature Service (WFS), Web Map Service (WMS) and Web Coverage Service (WCS), GWSC provides a single point of entry to the access of OGC compliant data services around the world to request any subsets of a multi-dimensional and multi-temporal geospatial data for a specific geographic region. It provides the capabilities to handle all details of different protocols internally so that users don't need to know the low level details of how to find and access these data. GWSC also can access tool-like Web services, such as Web Image Classification Service (WICS) and Web Coordinates Transformation Service (WCTS), to produce value-added data products. Moreover, in order for developing user's own more complex processing workflow that is used for further geospatial visualization and analysis, GWSC supports to build, instantiate, execute and register Web service chain.

This paper describes a project that develops an OPeNDAP server to serve satellite data to the Coordinated Enhanced Observing Period (CEOP) community. CEOP, which is built as the foundation of the World Climate Research Program (WCRP) in Cooperation with World Meteorological Organization (WMO) and the Committee on Earth Observation Satellites (CEOS) under the Framework of Integrated Global Observing Strategy Partnership (IGOS-P), seeks to establish an integrated global observing system for the water cycle to respond to both scientific and social needs. CEOP uses data from field observation, data assimilation, model outputs, and satellite remote sensing in research. The multi-source data integration is one of keys for the success of the CEOP program. Much of the satellite data identified in CEOP are Level-1B and Level-2 products. Data in these products are in Swath coordinates. While CEOP users commonly use the OPeNDAP protocols to access CEOP data for research, most of swath data are not available via this protocol. Instead, many space agencies have developed satellite data servers that implement the Open GIS Consortium (OGC)'s Web Coverage Service (WCS) Specification for serving satellite data to geospatial community. In order to provide satellite data to CEOP community, we developed a middleware, which act as a wrapper around an OpenGIS WCS implementation providing a gateway from the OPeNDAP protocols. The combination of the wrapper and any OGC-compliant WCS server acts as an OPeNDAP server. To provide the capabilities required to convert from Swath coordinates to an equirectangular latitude-longitude coordinate reference system, as well as perform grid cell interpolation and geo-spatial selection the server leverages the capabilities provided by an OGC WCS implementation. Basically, the middleware module does three things: 1). Translate the client requests in OpeNDAP protocols to WCS protocols and pass the requests to a WCS server; 2). Translate the server response in WCS protocols to DAP protocols and pass the response back to client; and 3). Handle the difference between the DAP protocols and WCS protocols. This paper discusses the details of the implementation.

NASA HDF-EOS Web GIS Software Suite (NWGISS) is a web-based data and information system that provides interoperable data accesses and services of HDF-EOS data to users. The software suite consists of a set of OGC standard compliant components, including a Web Map Server, a Web Coverage Server, a Catalog/Registries Server, a Multiple-protocol Geoinformation Client, and a Toolbox. Those components can work either independently or collaboratively. NWGISS can work with any HDF-4 based HDF-EOS data. The map server serves HDF-EOS data as maps to any OGC-compliant map clients. The coverage server allows GIS users to access multi-dimensional data at user specified geographic location, parameters, map projection, and formats in interoperable way. The catalog/registries server provides the catalog search capabilities to OGC-compliant catalog clients. The Multi-protocol Geoinformation Client enables users to access multi-source data served by OGC compliant web coverage, map, and feature servers and provides a set of data manipulation, processing, and analysis functions at user's desktop. The tool component consists of two-way translators between HDF-EOS and major GIS formats as well as the CreateCapabilities program that automatically creates the XML capability descriptions from the metadata in HDF-EOS. The combination of NWGISS servers and client provides interoperable, personalized, on-demand access and manipulation of EOS data to user community. Executables of all NWGISS components are free to any users and can be downloaded from http://laits.gmu.edu.

This paper describes the interoperable, personalized, on-demand data access and services (IPODAS) of remote sensing data provided by NASA HDF-EOS Web GIS Software Suite (NWGISS). NWGISS is a web-based, multiple OGC-standard compliant data distribution system. Currently, NWGISS consists of following components: a Web Map Server, a Web Coverage Server, a Catalog Server, a Web Coverage Client, and a Toolbox. Those components can work either independently or collaboratively. Executables of all NWGISS components are free to any users.

NASA EOS program is producing huge amounts of data in HDF -EOS format. Those data are valuable not only for global change research but also for resource and environmental management. GIS is one of the important tools for analyzing NASA's EOS data. Making HDF-EOS accessible to GIS through Internet will greatly enhance the interoperability and public use of EOS data. This paper describes a suite of web GIS software that makes HDF-EOS data available to GIS users based on Open GIS Consortium's (OGC) interoperability protocols. The software is called NASA HDF-EOS Web GIS Software Suite (NWGISS). NWGISS consists of the following components: a map server, a coverage server, a catalog server, a coverage client, and a toolbox. Those components can work both independently or collaboratively. NWGISS can work with all three types of HDF -EOS data, namely swath, grid, and point. Currently, the map server, compliant with OGC web mapping specification 1.0, has been developed and tested. The coverage server, which serves real data to GIS clients, has been developed and tested as a part of OGC WMT II activities. The catalog server provides catalog search capabilities to GIS clients. The state-full catalog server has been implemented and the http-based stateless catalog server is being implemented. The coverage client, which enables GIS users to access multi-source data served by OGC compliant web coverage servers, is being developed now. The toolbox consists of two -way translators between HDF-EOS and major GIS formats, as well as the CreateCapabilities tool that automatically creates the XML capabilities descriptions from the metadata in HDF-EOS files. Both tools are available now. NWGISS map and coverage servers have been used by NASA and other space agencies. NWGISS is free to data providers who want to serve HDF-EOS data to GIS clients.

Geospatial data is one of important sources of information for Earth system science research, environmental and natural resource management, decision-making, and other applications. However, current one-size-fit-all approach at data centers for geospatial data access and services cannot meet data users' requirements and expectations. Data users are calling for the interoperable, personalized, on-demand data access and services (IPODAS) that enables them to obtain data from multiple sources in the form exactly matching their requirements. This paper describes IPODAS and the way for providing IPODAS through OGC Web coverage service specification. It also describes IPODAS of NASA HDF-EOS data with two components of NASA HDF-EOS Web GIS Software Suite (NWGISS): the multiple protocol geoinformation client and the web coverage server.

NASA Earth Observing System (EOS) program is producing huge amounts of data that are vitally important for global human, economy and environment. However since these data are in HDF-EOS format, and can not be interoperated with and ingested by many GISs, thus it is highly desirable to make HDF-EOS data accessible to GIS users through Internet. GMU is pioneering the effort in developing OGC-compliant software, such as a software package NASA HDF-EOS Web GIS Software Suite (NWGISS), for making NASA EOS data available to general publics. This paper describes an important component of NWGISS, the Web Coverage Client (WCC). It enables the access of multi-dimensional and multi-temporal geospatial data from multiple coverage servers in the form that exactly matches users' requirements, regardless the original forms of the data in the servers. The easy-to-use and easy-to- install thick web client is the first web-based client in the world for GIS users to access the HDF-EOS data as well as other formatted data in an unified way, greatly enhancing the interoperability and public use of EOS data. Coupled with the NWGISS Server packages, WCC makes HDF-EOS data available to GIS users based on Open GIS Consortium's (OGC) interoperability protocols.