3‐D refractivity field from GPS double difference tomography

[1] 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.

[1]  A. Rius,et al.  Sensing atmospheric structure: Tropospheric tomographic results of the small-scale GPS campaign at the Onsala Space Observatory , 2000 .

[2]  Lars Peter Kruse.  Spatial and temporal distribution of atmospheric water vapor using space geodetic techniques , 2000 .

[3]  Hisanori Itoh.  True versus apparent arctic oscillation , 2002 .

[4]  Steven Businger,et al.  GPS Meteorology: Direct Estimation of the Absolute Value of Precipitable Water , 1996 .

[5]  Kazuro Hirahara,et al.  Local GPS tropospheric tomography , 2000 .

[6]  T. Herring,et al.  GPS Meteorology: Remote Sensing of Atmospheric Water Vapor Using the Global Positioning System , 1992 .

[7]  Ying-Hwa Kuo,et al.  Assimilation of Precipitable Water Measurements into a Mesoscale Numerical Model , 1993 .

[8]  D. C. Hogg,et al.  Measurement of excess radio transmission length on earth-space paths , 1981 .

[9]  Christian Rocken,et al.  GPS/STORM—GPS Sensing of Atmospheric Water Vapor for Meteorology , 1995 .

[10]  市川 隆一,et al.  Estimations of Atmospheric Excess Path Delay based on Three-Dimensional, Numerical Prediction Model Data. , 1995 .

[11]  Hajime Nakamura,et al.  Three-dimensional distribution of water vapor estimated from tropospheric delay of GPS data in a mesoscale precipitation system of the Baiu front , 2000 .

[12]  Alexander E. MacDonald,et al.  Diagnosis of Three-Dimensional Water Vapor Using a GPS Network , 2002 .

[13]  Rossella Ferretti,et al.  GPS PW assimilation into MM5 with the nudging technique , 2001 .

[14]  F. Webb,et al.  An Introduction to the GIPSY/OASIS-II , 1993 .

[15]  W. Menke.  Geophysical data analysis : discrete inverse theory , 1984 .

[16]  Alejandro Flores Jiménez.  Atmospheric Tomography Using Satellite Radio Signals , 2000 .

[17]  G. Ruffini,et al.  4D tropospheric tomography using GPS slant wet delays , 2000 .