Abstract:
A 3D - computerized tomography technique has been used to investigate the electron density
of the low - latitude ionosphere during the low solar minimum in 2008 over the East Africa
region. The 3D - tomography uses Damped Least Square inversion with the second order
Tikhonove Regularization (DLSTR) algorithm. The TEC used in the tomographic inversion
is obtained from the observables measured by a chain of station reciving transit satellite
transmission over the region. The algorithm employes electron density from NeQuick model
as apriori values. The electron density obtained from the inversion is a weighted combination
of the apriori electron density and that obtaind from GPS measurement. The results show that
the reconstructed electron density exhibits the required diurnal, latitudinal and longitudinal
variations consistent with the physics of plasma formation and transport