Measurement of electron temperatures in the lower ionosphere by detecting the space potential on the langmuir probe characteristic

Electron temperatures have been determined at Thumba on Nike Apache flight 10.11 (12 March 1967, 1857 hr IST) by the usual retarding potential analysis and by using an a.c. modulation technique for detecting the space potential on the Langmuir probe characteristic. Simultaneous measurements with the two techniques show that the space potential technique gives temperatures which are related to the temperatures obtained from the retarding potential analysis in a manner remarkably similar to the relations obtained by Booker and Smith as well as by Carlson and Sayers between radar temperatures and d.c. probe temperatures. This result is interesting in view of the fact that radar temperatures have been found to be in good agreement with the temperatures obtained by a.c. modulation techniques on satellite borne probes. The space potential technique is simple, requires limited additional electronics, does not make stringent demands on telemetry and can be easily adopted for rocket borne Langmuir probes