The Terminal Doppler Weather Radar (TDWR) has been deployed to 45 major U.S. airports to provide wind shear detection services and precipitation reflectivity data to controllers and supervisors. In addition, this sensor's characteristics complement make it well suited for additional applications. Its narrow beam and aggressive ground clutter suppression algorithms provide excellent data on boundary layer reflectivity and winds - in particular the locations of thunderstorm outflow boundaries. These data are known to be essential for providing high-resolution convective weather forecasts out to 2 hours. Similarly, its narrow beam is useful for detection of severe weather signatures (e.g., tornado vortices) with small azimuth extent. Relative to the Weather Service Radar 88-D (NEXRAD) it scans rapidly (e.g., surface updates once per minute), facilitating monitoring of rapidly evolving convective weather phenomena. It is typically located near to population centers and congested airspace, so that it is well situated for supporting weather services for operationally important areas.

This paper describes work underway to enhance the TDWR's capability to provide wind shear detection services in challenging conditions, and to improve the sensor's ability to support applications such as those described above. A Radar Data Acquisition (RDA) system retrofit will upgrade the transmitter, receiver and digital signal processing subsystems of the radar to improve the quality of the reflectivity and Doppler imagery generated by the system and to extend its instrumented range. Key objectives include improved rejection of ground clutter and range-folded weather echoes, and better handling of high-wind conditions where Doppler aliasing may occur. The flexible radar "front-end" architecture could, in principle, support other enhancements such as generation of additional base-data fields (e.g. spectrum width) and polarimetric and/or multi-frequency measurements. TDWR "front end" enhancements could support improved turbulence, icing, snowfall, and cloud monitoring services.

This paper will describe the processing architecture under development for the TDWR RDA retrofit, the basic algorithmic enhancements envisioned and the test program that is commencing in Oklahoma in the spring of 2002.

*This work was sponsored by the Federal Aviation Administration under Air Force Contract No. F19628-00-C-0002. The views expressed are those of the authors and do not reflect the official policy or position of the U.S. Government. Opinions, interpretations, conclusions, and recommendations are those of the authors and are not necessarily endorsed by the US Government.