A unified GPS dropsonde quality assurance and visualization software system

Over 16,000 NCAR GPS dropsondes have been released within and near tropical cyclones from various aircraft since 1997. They continue to be one of the main tools that provide both real-time information of the kinematic and thermodynamic structure of the TC and its environment and post analyses of these structures for research. The dropsonde provides a quasi-vertical profile of temperature, pressure, humidity, and wind from the aircraft altitude to the sea surface. The data are collected at a 2 HZ rate as the sonde descends with fall rates of 10-25 m/s, depending on altitude. The raw data from the dropsonde may contain large errors and needs to be quality-controlled (QC) before transmitting the observations for real-time use or before using the data for research purposes. Currently there are two software packages that provide the necessary quality control. One of these, ASPEN, was written and maintained by NCAR, runs on Windows PCs and is freely available for download. ASPEN is used by numerous researchers and for real-time transmission of dropsonde observations by the Air Force and on some NOAA aircraft. The other software package, Editsonde, is maintained by NOAA/HRD, but only runs on some very specific UNIX workstations. Editsonde has been used for many of the NOAA real-time dropsonde data transmissions and to create a database of quality-controlled observations from a limited number of the TCs sampled by dropsondes. The two software packages produce similar, but not identical, results for the QC process. ASPEN is easier to use but does not have all of the capabilities to view and modify the dropsonde data as does Editsonde. Recently, the Joint Hurricane Testbed program of NOAA has funded NCAR and HRD to produce a unified dropsonde quality assurance software package. This package is being designed to operate on multiple computer platforms, will have the ease of use for real-time applications, yet provide the added capability of more stringent quality control and data correction for research applications. The purpose of this poster will be to the describe new dropsonde QC software package and provide examples of it's use. The methodology, algorithm choice, and visual capabilities will also be discussed and presented.