Measurements in theE-layer with the Navy Viking rocket

A CW radio propagation experiment was conducted in the ionosphere with the Viking 5 rocket, launched at 10:18 hours MST on November 21, 1950, at the White Sands Proving Ground, New Mexico. Ordinary and extraordinary indices of refraction at 4.274 Mc were measured in the region surrounding the rocket. From these basic data, it was possible to determine the electron density continuously from 95 to 165 km and to show that the Lorentz polarization term should not be used at 4 Mc. In addition, the rapid decay to extinction of the extraordinary ray between 136 and 142 km was used to compute a value of 0.488 oersted for the earth's magnetic field at 139 km and to set an upper limit of 104 per second for the electron collision frequency at 139 km. The results of the Viking flight and also those of previous flights indicate a rapid increase in electron density beginning at 92 km and ending near 110 km. Between 110 and 165 km, the Viking data show that the electron density increased very slowly from 1.3×105 el/cc to 1.8× 05 el/cc. This distribution and similar evidence previously obtained suggest that during the daytime the E-layer probably remains dense up to the F-layers.