By Erol Ozan, Department of Engineering Management, and Paul Kauffmann, Department of Engineering Technology, Old Dominion University, Norfolk, Virginia

In aircraft-based meteorological data collection systems, selected aircraft (mainly commercial passenger and package carrier aircraft) are equipped with weather sensors and data link equipment. This is a relatively new concept, which has significant potential to improve weather forecasts. The National Weather Service (NWS) and the National Aeronautics and Space Administration (NASA) have plans to increase both the capacity and the number of aircraft-based sensor systems. Tropospheric Airborne Meteorological Data Reporting (TAMDAR) is a new version of these systems that NASA is currently developing.

The TAMDAR concept consists of sensor packages, information processors, and communications equipment carried aloft by participating aircraft. As these aircraft complete their scheduled flights, the TAMDAR system reports weather conditions to ground-based receiving stations that process and distribute this data into a national system for dissemination of weather information. The Federal Aviation Administration (FAA), NWS, and NASA have concluded that TAMDAR systems have potential to enhance the accuracy and completeness of weather data and the resulting weather forecasts.

In a recent project jointly sponsored by NASA and the FAA, a group comprising participants from the Old Dominion University (Norfolk, Virginia) departments of Engineering Management and Engineering Technology completed the TAMDAR Economic Feasibility Study to explore cost and benefit factors. As a follow-on project, NASA selected the group to develop a prototype economic TAMDAR Decision Support System (TAMDAR-DSS), which aims to reduce the operational costs of the TAMDAR system.

The primary objective of the TAMDAR-DSS research is to develop a simulation-optimization modeling approach (i.e., architecture) that can support trade-off analysis involving a given set of weather data points provided by a given combination of flights or carrier types, the cost of gathering weather data from those points, and the utility they provide to weather forecasters.

The TAMDAR-DSS has four main components: a GIS-based user interface and analysis unit, a data point utility estimator, a multicriteria simulation-optimization engine, and a flight pattern simulator. The data point utility estimator forms the basis of the system. Its parameters can be changed by the user via the user interface.

Choosing the GIS

The group selected ArcView software because of its extensive spatial data presentation and GIS capabilities. During the conceptual design phase of this TAMDAR-DSS project, the university group decided to focus on the design of the optimization strategy and meteorological data valuation. The group did not have time to build extensive geographical visualization features and GIS capability, which are required by the proposed system. ArcView provided them with all the visualization options and user interface capability they needed. One other important advantage of using ArcView is its compatibility with other software. The group used Visual Basic to build the user interface. For optimization and statistical analysis, they used S-Plus. Communication between ArcView and both Visual Basic and S-Plus was seamless.

To optimize the data collection in the TAMDAR-DSS, the group needed to calculate the value of individual data points. Consequently, the decision support system should generate these data sets. In the TAMDAR-DSS, the flight pattern simulator module generates the trajectories of flights and corresponding expected data pattern together with the geographical data point location and acquisition time. The geographical data point location includes latitude, longitude, and altitude information for each data point collected during each candidate flight. Users can also see color-coded representation based on data acquisition time by using ArcView software's interface. Users can evaluate spatial and temporal data coverage by selecting predefined ArcView themes.

For more information, contact Erol Ozan, Ph.D. candidate and research assistant, Engineering Management Department (e-mail: gozan@odu.edu), or Dr. Paul Kauffmann, primary investigator of TAMDAR-DSS project and chair of the Department of Engineering Technology (e-mail: pkauffma@odu.edu), Old Dominion University, Norfolk, Virginia.