P1.6 THE NEW WEATHER RADAR FOR AMERICA’S SPACE PROGRAM IN FLORIDA: A TEMPERATURE PROFILE ADAPTIVE SCAN STRATEGY Lawrence D. Carey 1 , William P. Roeder 2 , Kevin M. McGrath 3 , Walter A. Petersen 4 , and Wiebke K. Deierling 1 1 Earth System Science Center, NSSTC, University of Alabama in Huntsville, Huntsville, AL 2 45 th Weather Squadron, Patrick AFB, FL 3 Jacobs ESTS Group, NSSTC, Huntsville, AL 4 NASA Marshall Space Flight Center, Earth Sciences Office, VP-61, NSSTC, Huntsville AL 1. INTRODUCTION The 45th Weather Squadron (45 WS) is the U.S. Air Force unit that provides weather support to America’s space program at Cape Canaveral Air Force Station (CCAFS), NASA’s Kennedy Space Center (KSC), and Patrick AFB (PAFB) in east central Florida. The weather support requirements of the space program are very stringent (Harms et al., 1999). Since central Florida experiences the largest annual cloud-to- ground lightning flash density in the U.S. (Huffines and Orville, 1999), thunderstorms and their related hazards are important to operations at CCAFS/KSC. These hazards include lightning, convective winds, hail, and tornadoes. The 45 WS uses a dense network of weather sensors to meet the operational requirements in this environment (Roeder et al. 2003). One of the most important weather sensors to the 45 WS mission is the WSR 74C radar at PAFB (Roeder et al., 2005). This radar is near the end of its lifecycle and is being replaced by a new Radtec TDR 43-250 radar. This new radar provides significant benefits over the existing WSR-74C, including Doppler and dual-polarization capabilities (Roeder et al., 2009, this conference). A new fixed scan strategy was designed to best support the Florida space program (Roeder and Short, 2009, this conference). The fixed scan strategy represents a complex compromise between many competing factors and relies on climatological heights of various temperatures that are important for improved lightning forecasting (Roeder and Pinder, 2008) and evaluation of Lightning Launch Commit Criteria (LCC)(Roeder and McNamara, 2006). The Lightning LCC are the weather rules to avoid natural and triggered lightning strikes to in-flight rockets. The temperature layer from 0°C to -20°C is vital since most generation of electric charge occurs within it and so it is critical in evaluating the Lightning LCC and in forecasting lightning. The Lightning LCC also considers the ±5°C level to allow for rapidly developing convection. These are two of the most important missions of 45 WS. While one fixed scan strategy that covers most of the climatological variation (±2σ) of the 0°C to -20°C levels with high resolution ensures that these critical temperatures are well covered at all times, it also means that on any particular day the radar could be spending precious time scanning at angles covering less important heights over and around the launch pads at CCAFS/KSC. The paper describes an ongoing project to develop a user-friendly, Interactive Data Language (IDL) computer program that will automatically generate situation-dependent, mission-optimized radar scan strategies with user adaptive input of the temperature profile and other important parameters. By using only the required scan angles output by the temperature profile adaptive scan strategy program, faster update times for volume scans and/or collection of more samples per gate for better data quality is possible while maintaining high resolution at the mission critical temperature levels. The adaptive scan strategy will select beam angles based in part on vertical resolution mission requirements as defined by the half-power beam widths between vertically adjacent beams (Fig. 1). Figure 1. Depiction of the half-power beam gap. The half-power vertical beam gap is defined as the vertical distance between two adjacent radar beams from the bottom of the upper half-power beam width to the top of the lower half-power beam width, as shown above. The half-power beam width of the new radar is 0.95°.