Operational Quality Control of 50-MHz DRWP Wind Profiles for Space-Lift Support

The U.S. Air Force’s 45th Weather Squadron (45 WS) provides comprehensive operational meteorological services to the Eastern Range (ER) and the Kennedy Space Center (KSC). These services include weather support for pre-launch ground processing and day-of-launch operations by the Department of Defense (DOD), National Aeronautics and Space Administration (NASA), and commercial customers. In 1990, NASA installed a 50-MHz Doppler radar wind profiler (DRWP) at KSC to evaluate its applicability for measuring upper-level winds in support of space-lift operations.

Upper-level wind measurements are used in the evaluation of launch vehicle dynamic loads, structural stress analysis, and as input to steering parameter programs. Historically, balloons have provided the measurements used by the wind evaluation team. Currently, both the Shuttle and Titan programs augment balloon data with high-temporal resolution 50-MHz DRWP wind profiles to protect vehicles from rapid wind changes occurring between the last balloon release and the actual launch. A significant wind change during this period may delay the launch until additional upper-air data can be analyzed.

The ER and NASA have undertaken the challenging task of transitioning state-of-the-art instrumentation, such as the 50-MHz DRWP, into operational space-lift support. Because of the critical nature of the wind estimates, all upper-level wind data are manually quality controlled during launch countdowns. DRWP profiles are quality controlled by examining the wind velocity profiles in relation to the radar returns.

This paper describes the 50-MHz DRWP system, including a brief review of the hardware and signal processing strategy, and the operational quality control (QC) procedures currently implemented on the ER. The manual QC methodology and the interactive displays used to perform it are illustrated, and the training requirements for QC personnel are discussed.