Comment on “A method for detecting ionospheric disturbances and estimating their propagation speed and direction using a large GPS network” by James L. Garrison et al.


[1] The method presented by Garrison et al. [2007] is a simplification of the method presented in our uncited paper [Hernández-Pajares et al., 2006]. In this paper we extended the work (model and computations) presented by Orus et al. [2003] (cited in the work of Hernández-Pajares et al. [2006]), over four worldwide local networks, processed during 1 year or more, filtering out unrelated medium-scale traveling ionospheric disturbance events and using an exact analytical correction for the Doppler term (not incorporated by Garrison et al. [2007]).