RELATIONSHIP BETWEEN MEASURED VALUE OF RADIO WAVE PROPAGATION TIME AND PROPAGATION PATH OF RADIO WAVE

PURPOSE: To accurately measure the propagation time of a radio wave by deciding that the position of a radio wave radiation source is on a radio wave path or along its extension line. CONSTITUTION: It is assumed that a radio wave radiation point P is in a medium having a refractive index np and a dielectric constant p and an observation point A is in a medium having a refractive index nq and a dielectric constant q . It is considered that an estimated radiation source point P' is not on a radio wave path PCA but on a PDA. It is assumed that the incident angle and the refractive angle of the radio wave at a point C are θp , θq and those at a point D are p , q . Then, according to Fermat's principle, sinθp /sinθq =( p / q )=nq /np is satisfied and sin p /sin q =( p / q )=np /nq is satisfied. However, the point C is different from the point D. In order to satisfy both the formulae, the points C and D must coincide with each other. Therefore, if an observer erroneously estimates the point P as the point P', the point P' must exist on the path PCA or along the extension line exceeding the point P.