Welcome to the Washington/Northern Virginia Chapter of IEEE/GRSS

Technical Meeting

Wednesday, October 31, 2007 at 3:30pm

NASA Goddard Visitor Center

(refreshments available at 3:00pm)



Dr. Yuqi Bai

Research Assistant Professor

Center for Spatial Information Science and Systems, George Mason University

Effective discovery of geospatial data: a geospatial catalogue's perspective

Every scientist has his own way of finding satellite images of interest for their research work. But they might not notice that many research efforts have been directed behind the scenes to fulfill this "geospatial data discovery" task.
This presentation will touch on the following aspects of data discovering issues:
1) Basic knowledge of Internet, HTTP protocol and GET/POST bindings.
---It would be appropriate to know some underlying techniques that enable digital information being transformed between publishers and consumers.
2) Metadata - problems, background, standards (ISO, OGC, US), use cases.
---Metadata plays a key role in facilitating information discovery. The way of promoting indirect geospatial data discovery through direct discovery of metadata has been extensively used world wide.
3) Catalogue system - problems, background, systems (e.g. NASA EDG, NASA ECHO), standards (OGC).
---Besides metadata information, the protocol, message and binding issues are dealt with in Catalogue systems.
4) Catalogue federation - problems, challenges, pioneering systems (GMU CFS).
---It is very desirable if those catalogues can be integrated into a catalogue federation, which will present a well-known metadata model and interface protocol to users and hide the complexity and diversity of the affiliated catalogues behind the interface. Challenges and problems in dealing with the metadata conceptual models, query languages, and communication protocols will be analyzed and proposed federation strategies and the operational federation system will be introduced.


Dr. Yuqi Bai, research assistant professor: Dr. Yuqi Bai has more than 10 years of dedicated research on Web-based geospatial information interoperability and integration, Geospatial Metadata, Geospatial Catalogue Service, and Geospatial Catalogue Federation. He received his B.S. in Computer Science and M.S. in Software Engineering from China University of Geosciences in 1997 and 2000 respectively, where he finished his M.S. dissertation of “The research and implementation of Web-based Geographical Information Systems”. He earned his Ph.D. degree in Cartography and Geographical Information Science from the Institute of Remote Sensing Applications, Chinese Academy of Sciences in 2003, with a dissertation of “World Wide Web Geospatial Information Search Engine”.

Yuqi is the author of “GMU CSISS Catalogue Federation Service”. This pioneering Catalogue Federation Service system is capable of performing distributed and integrated metadata discovery over three distinct geospatial catalogue services: the NASA Earth Observing System (EOS) ClearingHOuse (ECHO), the GMU OpenGIS Catalogue Service for Web (CSW), and the U.S. Department of Energy (DOE) Earth System Grid (ESG) Simulation Data Catalogue. This product is operational in the NASA funded GeoBrain project. It enables education community users to discover the online datasets in NASA data pools, the GMU Spatial Database, and the DOE ESG LLNL Simulation Database in a convenient and standard way.

Yuqi is the author of “GMU CSISS OGC CSW Wrapper for NASA ECHO”. This product provides an OGC-compliant Catalogue Service discovery interface for NASA ECHO. This is the only available operational system that provides this value-added functionality for NASA ECHO. This package was initially developed in 2004, and has been continually updated to be compatible with each ECHO release after that.

Yuqi is the task lead and a key developer in implementing the GEOSS Registry System. This system will develop Universal Description, Discovery and Integration (UDDI), OASIS ebXML-ebRS, and OGC CSW interfaces to be accessed by other GEOSS applications, including GEOSS Web Portal solutions. This system is the backbone of the GEOSS Clearinghouse, a new international effort of providing integrated search capability across the distributed and heterogonous catalogues and their registered resources.

Yuqi now is providing technical support to the NASA Goddard Earth Science Data and Information Services Center (GES DISC) on NASA ECHO system integration, and image subsetting for the Coordinated Energy and Water Cycle Observations Project (CEOP).

His findings, lessons-learned and research results have been published in several professional journals, books and international meetings, including the Journal of Photogrammetric Engineering & Remote Sensing, the Encyclopedia of Geographical Science, Encyclopedia of Geoinformatics, the IEEE International Geoscience and Remote Sensing Symposium, and the International Society for Photogrammetry and Remote Sensing technical meeting.