A COMPLETELY INTEGRATED , COST − EFFECTIVE , LOCAL DATA ASSIMILATION AND FORECASTING SYSTEM TO SUPPORT SPACE LAUNCH RANGE OPERATIONS

Weather plays a critical role in the planning and execution of spacecraft launch operations at both the Eastern Range (ER), located in Florida, and the Western Range (WR), located in California. Each launch vehicle has specific tolerances for wind shear. Cloud cover, temperature, and lightning constraints are common for all launch vehicles. The presence of convective activity in the vicinity of the range can be significant due to the potential for lightning strikes and electrostatic discharge. In the event of a launch mishap, toxic clouds have the potential to endanger ground personnel, thereby requiring high−resolution wind and stability information for input into atmospheric dispersion models used for risk−mitigation prior to launch and as an emergency response tool. An Air Force program to modernize and standardize the command and control infrastructure of both ranges, known as the Range Standardization and Automation (RSA) program, has been underway for several years. Included in this upgrade is a task to improve the systems used by the weather squadrons for monitoring and forecasting weather conditions in support of launch and emergency response activities. The Forecast Systems Laboratory (FSL) has been involved in this effort since 1996, when Observation Simulation and Sensitivity Experiments (OSSEs) were performed to determine optimum placement of the various observing systems being acquired. Additionally, FSL was funded to develop a data assimilation and forecast system using the Local Analysis and Prediction System (LAPS, Albers et al. 1996). The LAPS analysis was coupled with the Colorado State University Regional Atmospheric Modeling System (RAMS) as a prototype for this data assimilation system. The planned configuration consisted of a coarse nest with a grid spacing of 16 km and a fine nest with a grid spacing of 4 km. To meet the operational timelines, which require that a 24−h forecast be produced within 6 h of wall time, the domains were very limited in size, using 40 x 40 horizontal points. Since that decision was made, the cost of computational power has dramatically decreased, and it is now feasible, within the budget of the program, to expand the size of the domain and add a third nest to approach the objective requirement of 1 km grid spacing. Additionally, a decision was recently made by the Air Force and the primary RSA contractor, Lockheed Martin Mission Systems, to leverage other work being done by FSL on behalf of the National Weather Service (NWS). The program has selected the Advanced Weather Interactive Processing System (AWIPS) as the mechanism for ingesting and interacting with all of the standard and range−unique meteorological data. To maximize performance while minimizing cost, the version of AWIPS being tailored for the RSA project will use relatively inexpensive PCs running the Linux operating system. Details of the RSA AWIPS implementation are discussed in Wilfong et al. (2002). This paper discusses the details of the data assimilation and forecasting system, including the recent improvements made to the LAPS analysis, the selection and configuration of the forecast model, the revised domain configuration, and how the data assimilation and forecast system is integrated within AWIPS. The paper concludes by covering issues related to running forecast models within the AWIPS environment and future plans for the RSA assimilation system. ___________________________________________