Verification of atmospheric temperature and moisture profiles derived by GPS radio occultation technique
A radiosonde is an instrument carried aloft, primarily by weather balloons, to measure and transmit various atmospheric parameters. Radiosonde observations have played a critical role in the measurements of atmospheric information and been a main point of reference for metrological and climatical studies and prediction. Atmospheric profiles of temperature, pressure, humidity and wind profiles have been measured from radiosonde in meteorology in the past sixty years. The advent of GPS and global navigation satellite system (GNSS) technology and its application for precise tracking of low earth orbiting satellites has opened new opportunities for atmospheric studies through radio occultation techniques. Radio occultations have long been used in the remote sensing of planetary atmosphere. Recent studies suggest that GPS RO procedure is a promising tool for global climate change studies and numerical weather prediction through which atmospheric parameters can be determined with a high degree of accuracy. This paper compares atmospheric profiles of temperature, pressure and water vapor derived from the LEO satellites with radiosonde measurements in selected areas of Australia. Level 2 atmospheric and wet profile measurements obtained from the Constellation Observing System for Meteorology, Ionosphere, and Climate Data Analysis and Archival Center with radiosonde data obtained from the archive of the National Climate Centre, Australian Bureau of Meteorology (BOM) are compared. Statistical and visual comparison shows that the meteorological information derived from GNSS RO fits very well with that from radiosonde observations. Preliminary research has demonstrated the potential to use the GNSS RO techniques for the retrieval of meteorological information such as temperature, pressure and refractivity. This paper will present the latest developments of the joint research project between BOM and RMIT University and our vision of further research will be given.