Tomographic Reconstruction of Neutral Atmospheres using Slant and Horizontal Wet Delays achievable through the processing of signal observed from small GPS networks

This work deals with an innovative implementation of tomographic techniques for the three dimensional reconstruction of water vapour in atmosphere. Observables for this technique are Slant Wet Delay measurements collected from small networks of GPS receivers. This work uses simulated data. Slant Wet Delays were computed considering climatological atmospheric models plus Gaussian noise. A final reconstruction of a 4x4x10 voxels grid characterizing a tropospheric volume with about 1 km vertical and 6 km horizontal resolution has been considered. A maximum fractional error on wet refractivity varying from -2% to 6% has been computed. The same technique has also been applied to GPS observables simulated using radio soundings data. In this case results are appreciable only if atmospheric horizontal limb soundings can also be taken into account. Finally, the work carries out an assessment of the sensitivity to the seasonal variations of the wet refractivity distribution.