Improving the Vertical Resolution of Ionospheric Tomography with GPS Occultations

Authors: 
Rius, A., Ruffini, G., Cucurull, L.

Abstract. We combine GPS/MET data from 29 occul-
tations and IGS ground data collected from 160 stations
around the world to perform stochastic tomography of
the ionosphere with a 4×20×20 global grid of voxels ex-
tending from 200 to 650 km above the mean surface of
the Earth. A correlation functional approach that lim-
its the spatial high frequency content of the images is
used, and a Kalman filter is applied in the time direc-
tion. The combination of ground and occultation data
and the use of smoothing techniques is robust enough for
vertical resolution in this four-layer model analysis. We
discuss the role of noise on the choice of the correct range
of eigenvalues in the inversion problem, and the impact
of occultation data, showing that ground data alone is
insufficient for vertical resolution even in a three-layer,
noise-less simulation.
 

Date of publication: 
1997
Reference: 
Geophysical Research Letters, Vol.24, No.18, 2291-2294, 10.1029/97GL52283, 1997.