Error Aware Near Real-Time Interpolation of Air Quality Observations in GEOSS

This paper focuses on information system interoperability and uncertainty related to integrating standards-based sensor web observation services and data with standardized, web-based geoprocessing services. The work presented in this paper was conducted with the Air Quality and Health Working Group as part of the Global Earth Observation System of Systems Architecture Implementation Pilot, Phase 3 (GEOSS AIP). The goal of the GEOSS AIP is to build a system of resources, including data and data processes that are loosely coupled and made interoperable through a service architecture based on open standards. The Model Web [1] is a blueprint vision where GEOSS services can be flexibly coupled to create workflows that convert raw, low-level sensor data into aggregated information useful to various decision makers. A frequently encountered problem in building such Model Webs is that sensor data are obtained only at a limited, fixed number of spatial locations and points in time, whereas information about the attributes measured by these sensors is needed at different locations and/or time points, or for larger regions. Interpolation methods solve this problem by utilizing available sensor observations to estimate measured attributes at the locations, regions, and times where and when they are required. Since the interpolation process involves estimating new values from existing values, the results of the interpolation are made more useful when they include estimation errors derived from the number, distribution, and quality of the existing values.