IONOSPHERIC BACKSCATTER OBSERVATIONS AT MILLSTONE HILL
Abstract
Studies of the electron-density, electron and ion temperatures in the F-region were made by means of ground-based radar observations at the Millstone Hill Radar Observatory. A 70-meter parabolic antenna directed vertically and a 2.5-Mw pulse radar operating at 440 Mcps were employed for these measurements which were conducted for periods of 30 hours at approximately weekly intervals throughout 1963. Examination of the echo power as a function of height leads to a profile of electron density with height, provided the electron and ion temperatures are the same (T sub e = T sub i). Additional measurements of the spectra of the signals corresponding to different heights permit the ratio T sub e/T sub i to be determined and, where this is different from unity, the observed profile can then be corrected for the effect on the scattering introduced by the inequality in temperature. Results of observations extending over a period of one year from February 1963 to January 1964 are presented. The ratio T sub e/T sub i achieved a maximum value approximately 2.0 to 2.6 at a height of about 300 km soon after down, irrespective of the season. There was little change in height dependence in this ratio throughout the daylight hours, and at sunset the ratio fell with a time constant of the order of an hour. At night T sub e/T sub i was occasionally close to unity, but more often a significant difference remained in the temperatures at all heights.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 22, 1965
- Accession Number
- AD0616607
Entities
People
- John V. Evans
Organizations
- Massachusetts Institute of Technology