A Radio Method of Estimating the Height of the Conducting Layer

Abstract

IN a recent note we have outlined a method of estimating the height of the conducting layer by means of radio waves (M. A. Tuve and G. Breit, Terr. Mag., vol. 30 (1925), pp. 15–16). Through the co-operation of the U.S. Naval Research Laboratory, Bellevue, Anacostia, D.C., we have obtained definite indications of reflections such as would take place from the layer and some estimates of its height. The method used consists in sending out interrupted high frequency wave-trains and observing the wave-form of the received signal. Each wave-train received manifests itself as a temporary rise in the detector current of the receiving set. One particular wave-train at the transmitter gives rise to two received wave-trains at the receiver if a single reflection takes place. One of these trains travels over the ground and the other by way of the layer. Thus the detector current is forced to rise at two different times by the same wave-train from the transmitter and an oscillogram of the detector current shows two humps generally of unequal size.