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3‐D refractivity field from GPS double difference tomography
Author(s) -
Troller M.,
Bürki B.,
Cocard M.,
Geiger A.,
Kahle H.G.
Publication year - 2002
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2002gl015982
Subject(s) - radiosonde , global positioning system , troposphere , meteorology , remote sensing , environmental science , geodesy , tomography , geology , geography , computer science , physics , optics , telecommunications
GPS meteorology can be successfully used to model the tropospheric refraction effect on radiowave signals. We describe an approach to estimate and model the spatial distribution of the tropospheric water vapor. We refine the tomographic software package AWATOS which is based on the assimilation of GPS double difference observations. The observations are allocated to a voxel model, which is defined according to the distribution of the GPS stations. Performing a least‐squares adjustment, the refractivity of each voxel is determined. Tests of the software are performed, based on simulated and real data. The latter were obtained during a dedicated field campaign on the Big Island of Hawaii. The tomographic profiles are compared with radiosonde data. The results obtained for continuous atmospheric conditions fit well, whereas larger differences occur in discontinuous atmospheric weather conditions. Overall, an accuracy of 5–20 ppm (refractivity units) has been achieved.