RESUMEN
Geographic information provides the basis for many types of decisions ranging from simple path finding, to the sustainable management of environmental conditions. Producing such information is a time consuming and costly endeavor. Data sharing on the web is an avenue to increase the efficiency of the practices. This paper scientifically examines the new emerging technologies namely, internet, geographic markup language [GML], and observation and measurement models, to construct an interoperable repository for air quality sensors measurements. The paper also elaborates on the design and implementation of a web-based air quality information system [AQIS] for the city of Tehran. In-situ sensors measure ozone [O[3]], carbon monoxide [CO], sulfur dioxide [SO[2]], nitrogen dioxide [NO[2]] and particulate matters [PM] in polluted metropolitans. Providing real-time air quality information can improve the decisions of the pertinent environmental organizations. Using GML for encoding sensors observations makes it possible to build an interoperable repository that is independent of platforms and vendors. Providing query possibilities based on monitoring stations, sensor names [pollutants], date and time intervals, and spatial query on the AQIS interfaces are the major functions of this system. Although standardized, it was concluded that the use of GML as data format increases the size of GML document. In addition, the developed system provides no map based results for the clients. Therefore, it is required to be improved by adding more GIS functions