DIFFERENTIAL ABSORPTION IN THE<i>D</i>AND LOWERS-<i>E</i>REGIONS

Abstract

A method of measuring electron densities in the D region, making use of the Faraday effect is given. At noon on a day of high absorption, 2,000 el/cc were measured at White Sands Proving Ground, New Mexico, at an altitude of 76 km. The technique also makes possible the determination of the differential absorption, by measuring simultaneously the sum and difference of the amplitudes of the two magneto-ionic components at 7.754 Mc as the rocket rolls. None was found over the range 60 to 88 km. A slow increase then occurred up to 94 km, whereupon it increased very rapidly to a value of ½ per km at 96 km. Experimental difficulties prevented higher altitude measurements.