Air Quality uFIND: User-oriented Tool Set for Air Quality Data Discovery and Access

Historically, there have been major impediments to seamless and effective data usage encountered by both data providers and users. Over the last five years, the international Air Quality (AQ) Community has worked through forums such as the Group on Earth Observations AQ Community of Practice, the ESIP AQ Working Group, and the Task Force on Hemispheric Transport of Air Pollution to converge on data format standards (e.g., netCDF), data access standards (e.g., Open Geospatial Consortium Web Coverage Services), metadata standards (e.g., ISO 19115), as well as other conventions (e.g., CF Naming Convention) in order to build an Air Quality Data Network. The centerpiece of the AQ Data Network is the web service-based tool set: user-oriented Filtering and Identification of Networked Data. The purpose of uFIND is to provide rich and powerful facilities for the user to: a) discover and choose a desired dataset by navigation through the multi-dimensional metadata space using faceted search, b) seamlessly access and browse datasets, and c) use uFINDs facilities as a web service for mashups with other AQ applications and portals. In a user-centric information system such as uFIND, the user experience is improved by metadata that includes the general fields for discovery as well as community-specific metadata to narrow the search beyond space, time and generic keyword searches. However, even with the community-specific additions, the ISO 19115 records were formed in compliance with the standard, so that other standards-based search interface could leverage this additional information. To identify the fields necessary for metadata discovery we started with the ISO 19115 Core Metadata fields and fields that were needed for a Catalog Service for the Web (CSW) Record. This fulfilled two goals - one to create valid ISO 19115 records and the other to be able to retrieve the records through a Catalog Service for the Web query. Beyond the required set of fields, the AQ Community added additional fields using a combination of keywords and ISO 19115 fields. These extensions allow discovery by measurement platform or observed phenomena. Beyond discovery metadata, the AQ records include service identification objects that allow standards-based clients, such as some brokers, to access the data found via OGC WCS or WMS data access protocols. uFIND, is one such smart client, this combination of discovery and access metadata allows the user to preview each registered dataset through spatial and temporal views; observe the data access and usage pattern and also find links to dataset-specific metadata directly in uFIND. The AQ data providers also benefit from this architecture since their data products are easier to find and re-use, enhancing the relevance and importance of their products. Finally, the earth science community at large benefits from the Service Oriented Architecture of uFIND, since it is a service itself and allows service-based interfacing with providers and users of the metadata, allowing uFIND facets to be further refined for a particular AQ application or completely repurposed for other Earth Science domains that use the same set of data access and metadata standards.