Remote sensing of Atmospheric Integrated Water Vapor along Slant Paths Using Ground Based GPS

Abstract

AbstractSensing of integrated water vapor along slant paths using ground‐based GPS receivers is the basis of getting the three dimensions distribution (water vapor tomography) of water vapor around the observation site. The principle of remote sensing of water vapor along slant paths using GPS is described in this paper. Wet gradient and the post‐fit residuals were used to derive the nonisotropic component of water vapor in different azimuth above the GPS receiver, and then slant path water vapor was derived. In order to validate the accuracy of GPS observation, water vapor radiometers (WVR) were used to observe integrated water vapor along slant paths accompanying the GPS receivers. Comparisons between WVR and GPS observations at different sites and periods show that root‐mean‐square error is less than 4mm. Therefore, slant path water vapor amount can be accurately retrieved using this method, which is suitable for near real‐time application in remote sensing and detection of atmosphere. Ground‐base GPS measurement of water vapor has the advantage of all‐weather continued observation. It is a supplement to traditional water vapor observation and provides accurate continued water vapor data for climate research. The application with GPS receiver network will provide good initial condition for numerical weather prediction and finally contribute to the improvement of weather forecasting accuracy.