The new Vaisala RS92 radiosonde family was first introduced at AMS 2003 annual meeting in February 2003. At that time, the key performance indicators for the RS92 radiosonde performance were given. Continuous wind data availability with code correlating GPS (global positioning system) windfinding and a high level of PTU (pressure, temperature, humidity) measurement ability were offered to the meteorological community.

Now, after the introduction of the new radiosonde, it is a good opportunity to follow up how these performance indicators have been realized in actual use, both in extensive test series and in the real operational environment. These improvements in the new radiosonde including accurate and reliable measurements of PTU as well as accurate and robust GPS wind data availability, serve also as major benefits to reliable weather prediction.

This paper will concentrate on analysis of the performance, reliability and accuracy of the RS92 code correlating GPS technology and to demonstrate PTU performance from the optimized sensors in this new radiosonde. In addition, the experiences with the RS92 Loran-C windfinding technology version will be discussed. A special emphasis will be on improvements in RS92 humidity measurement capability by use of a pre-launch reconditioning of the radiosonde humidity sensors. This procedure significantly mitigates the phenomena of dry bias in radiosonde measurement.

The global implementation of Vaisala RS92 radiosondes will represent a major change in current operational upper air instrumentation. User comments from early adopters will provide insight to the practical change from previous radiosonde models to the new Vaisala RS92 Radiosondes.