Under the condition of an unstable, inhomogeneous and anisotropic ionosphere, some relations among the dynamic parameters of the ionosphere and the observables of HFradio echoes reflected from the ionosphere are derived from the general ray equations. On the basis of these relations, a method is proposed to invert the height profile of the electron density,
N(Z), and the height profile of the normal velocity,
V(Z) of the constant electron density surface from the observed Dopplionogram, gonionogram, ionogram and rangionogram. Furthermore, comparing the possible combination of the radio wave obserables which are necessary and sufficient for the determination of the height profiles of
V(Z) and
N(Z), the authors suggest a new operation mode of ionosonde to observe the large scale ionospheric disturbances such as the gravity waves from a single station. This may be the theoretical basis for data analysis and instrumental improvement of modern ionosonde.