Studies of the effectiveness of the water vapor sensing system, WVSS-II, in supporting airline operations and improved air traffic capacity

The Water Vapor Sensing System (WVSS-II) has been in operational use at United Parcel Service (UPS) and Southwest Airlines (SWA) beginning in early October of 2009. The WVSS-II is designed for in-situ measurement of atmospheric water vapor from commercial aircraft, in conjunction with the U.S. NWS MDCRS program and the global AMDAR program. The WVSS-II uses Tunable Diode Laser Absorption Spectroscopy technologies to measure water vapor concentrations along the aircraft flight path, with data communications to the ground by commercial carriers using ACARS. At present, UPS operates WVSS-II sensors on 25 aircraft, while SWA is in the process of installing 31 aircraft with WVSS-II sensors, with plans for up to an additional 36 installations by the end of 2012. This paper will provide an overview of the end-to-end processing of WVSS-II observation data, summarize the intercomparisons of the WVSS-II data with other in-situ platforms, and evaluate the effectiveness of the WVSS-II in supporting operational decision making for airline operations. Various operational case studies will be provided to highlight and estimate the benefits these new observations provide to airline operations and improved air traffic capacity.