Launch Weather Decision Support System

Launch safety and efficiency requires timely and accurate wind, thermodynamic and pressure information from the surface to 20 km height, and lightning risk identification. A Doppler radar now provides wind measurements that satisfy this requirement at the Eastern Test Range. Thermodynamic soundings are provided by intermittent radiosondes on launch day. Typical intervals of an hour or more between radiosonde launches and drift distances of 100 km or more at 20 km height limit their timeliness and accuracy in characterizing the atmosphere along the launch path. NASA is seeking a thermodynamic remote sensing system with higher timeliness and accuracy, in clear and cloudy conditions. Current Radiometrics (RDX) microwave radiometer profilers provide continuous thermodynamic profiles from the surface to 10 km height, with radiosonde equivalent accuracy up to several km height, with decreasing accuracy at higher levels. The RDX profiler also provides cloud and atmospheric stability information that can be used to identify lightning risk. Improved thermodynamic profiler accuracy, and pressure profiling capability, have been demonstrated using variational retrieval methods that include model gridded analysis. Variational retrievals can also extend accurate thermodynamic and pressure profiling to 20 km height. We propose to implement and automate variational retrieval and lightning risk identification methods in a Launch Weather Decision Support System. The LWDSS will provide timely and accurate thermodynamic, pressure and lightning risk information needed to improve launch and airport safety and efficiency. More »