Comparison of Selected In-situ and Remote Sensing Technologies for Atmospheric Humidity Measurement
In this study humidity measurements of Vaisala Radiosondes RS41 and RS92 were compared against water vapor pressure profiles measured with a high capability water vapor Raman lidar situated at Jet Propulsion Laboratory Table Mountain Facility in California, USA. Test flights were conducted as dual soundings in various humidity conditions. Another performance analysis was made by comparing IPW columns calculated from the radiosonde relative humidity measurements to simultaneous IPW measurements of microwave radiometers and/or GPS receivers of the same site. Comparative soundings were also conducted at Arctic Research Center of Finnish Meteorological Institute in Sodankyla, Finland. In these soundings a Cryogenic Frostpoint Hygrometer (CFH) was used as an in-situ reference instrument.
This comparison of various humidity measurement technologies confirmed the good performance of both operational radiosondes and the Raman lidar instrument. It also gave valuable information about differences between in-situ and remote sensing methods for humidity measurement.