A team at the University of Delaware is developing a real-time data display system for data being collected and archived as part of the Delaware Environmental Observing System (DEOS). DEOS is a real-time system dedicated to monitoring environmental conditions across the State of Delaware, the near-shore coastal waters and the Delaware Bay, and adjacent regions of Maryland, Pennsylvania, and New Jersey. It is primarily a tool for decision makers involved in emergency management, transportation, agriculture, and environmental management. It is a cooperative venture with a number of state and federal agencies participating, as well as the climate offices from Kentucky and Virginia.

This interface will be the central component of the DEOS Interactive Visualization and Analysis System (DIVAS), which will display the surface weather observations from DEOS and National Weather Service radar estimates of precipitation. In addition, through the use of the Spatial Meteorological Analysis in Real-Time System (SMARTS), DIVAS will present in both digital and graphical form the results of spatial interpolation of the station data to a high spatial resolution grid and calibration (“ground-truthing”) of the radar rainfall estimates. Additional derived environmental variables (e.g., evapotranspiration rate, apparent temperature, equivalent potential temperature) also are displayed by the DIVAS system.

DIVAS will be based on a server application using the Environmental Systems Research Institute (ESRI)’s new ArcGIS 9 Server to display station data, interpolated fields, and bias-adjusted radar estimates of precipitation. ArcGIS Server is a modular, scalable system consisting of several components that are distributed across multiple machines. The components consist of a GIS server, a web server, and desktop applications for end users to connect to ArcGIS web services over the Internet.

DIVAS provides basic map navigation capabilities to pan and zoom around Delmarva, dynamically display real-time weather information overlaid with political boundaries, roads, and streams for spatial reference, identify features on a map by pointing to them, select features within a specified distance of other features or within an area of interest, find and select features using structured query language (SQL) expression, and extraction of information for user defined spatial area and time period of interest to the end user. DIVAS allows a user, for example, to highlight the nearest weather observation sites to a location of interest or contained within a county, or highlight all geographic areas that receive greater than a user-specified amount of rainfall during the last three hours to track potential areas of flooding.