Embed Size (px)
Citation preview
Air Quality Data Services: Application of OGC specifications
Air Quality Data: Multi-dimensional, multi-source, multi-format
Point observations are collected by fixed-location sensors and mapped into a relationship database.
The station information (lat, lon, name, etc) is captured in a station table that can be serve the station information as a WFS.
The descriptive information identifying the type of sensor, such as pollutants measured, method used, sampling frequency, and sampling duration are collected in parameter table. This information can be encoded in SensorML and accessed through SOS.
A central fact table of observations is continually updated as newer observations are collected. The observations are associated with a station id, date/time, and parameter and can be served as a WCS or SOS and visualized through a WMS or other viewer services.
Application of OGC Specifications to Air Quality Information SystemsCenter for Air Pollution Impact and Trend Analysis (CAPITA) Washington University in St. Louis
Contacts: Stefan Falke ([email protected]), Rudolf Husar ([email protected])
OGC: Open Geospatial Consortium Specifications
DataFed: Interoperability among distributed data sourcesData Federation (www.datafed.net) is a web-based infrastructure for distributed data access and collaborative processing/analysis of air quality data.
Research supported by:
Web Map Service (WMS)
Web Feature Service (WFS)
Web Coverage Service (WCS)
Sensor Observation Service (SOS)
IN43B-09
Air quality data are collected by multiple sources including surface monitoring networks, air-borne measurements, and satellite-borne sensors.
multidimensional data model
Station-Point SQL Server, Files…
Sequence Image, file
nDim Grid OpenDAP netCDF, …
Other Traject., Events, Pics
Characterizing air pollution with these data involves multi-dimensional analysis over x,y,z spatial dimensions, the temporal dimension, and across multiple parameters.
The Open Geospatial Consortium (OGC) specifications focus on the spatial dimensions (maps) but can be extended and adapted to support standardized queries to non-spatial dimensions of the data space.
WMS ServerGetMap
image
http://webapps.datafed.net/ogc_EPA.wsfl?SERVICE=wms&REQUEST=GetMap&VERSION=1.1.1&SRS=EPSG:4326&STYLES=&LAYERS=NEI_EGU.SO2&BBOX=-127.00,24.00,-66.00,50.00&TIME=1999-01-01T00:00:00&FORMAT=image/png&EXCEPTIONS=application/vnd.ogc.se_inimage&TRANSPARENT=TRUE&BGCOLOR=0xFFFFFF&WIDTH=700&HEIGHT=350
GetMap Request
Sensor Modeling Language (SensorML)
WMS Client
http://webapps.datafed.net/ogc_EPA.wsfl?SERVICE=wcs&REQUEST=GetCoverage&VERSION=1.0.0&CRS=EPSG:4326&COVERAGE=EPA_CAMD_HOUR.SO2_MASS&FORMAT=NetCDF-table&BBOX=-82.4606,42.9258,-82.4606,42.9258,0,0&TIME=2002-04-01/2002-04-30&WIDTH=700&HEIGHT=350&DEPTH=99
GetCoverage Request
WCS Server WCS Client
GetCoverage
GeoTiff,HDF,netCDF,…
netCDF
Other specs:
• multi-dimensional access to measurement data and sensor descriptions
• standard for requesting and delivering spatial map images
• standard for query-based access to and delivery of multi-dimensional data
• models and XML encoding of sensors
• query and delivery of discrete feature data
Implementation of OGC specifications makes the data available in multiple formats and usable by a variety of clients as either maps, time series plots, or tables.
