METEOR TRAIL MEASUREMENTS BY RADIO ECHO DETECTION MEANS.

The report is concerned with the investigation of upper atmosphere densities, pressures and temperatures from observations of radio echoes from meteor trails. The heights of meteor trails are determined using radio direction finding techniques. Measurements of meteor velocity can then be used together with theories of meteor ionisation to give atmospheric pressures and scale heights. The rate of decay of echo amplitude, which depends directly upon the molecular diffusion coefficient, also gives a measure of atmospheric density. Mean atmospheric profiles between 80 and 100 Km. for two days in January 1958 have been determined, and are shown to be in good agreement with the I.C.A.O. atmosphere. The diurnal variation in atmospheric density has also been investigated, and at a height of approximately 95 Km. preliminary measurements suggest that the density varies by almost a factor of 2 to 1 throughout the day. If this result is verified as more records are analysed, then the adoption of a standard atmosphere for this region would have little significance. Author