Use of GPS Phase Measurements to Improve Vertical Refractivity Profiles in the Boundary Layer

The primary scientific objective of this research is to develop GPS sounding techniques for ground based atmospheric profiling. Atmospheric profiling with GPS from space has been demonstrated (i.e. Ware et al. 1996, Rocken et al., 1997). Ground based GPS receivers have been used to determine integrated atmospheric water vapor above a site (i.e. Rocken et al., 1993), and along the ray paths to GPS satellites (Ware et al., 1997), but profiling techniques with ground-based GPS observations are still under development. Because of the large number of globally operating permanent GPS networks, ground-based profiling, if it proves feasible and accurate, will provide a large additional data set for atmospheric science and weather prediction applications. This data set will be especially useful for detailed monitoring of water vapor, one of the most important and yet least well defined atmospheric constituents.