Evaluation of electron and ion densities in the middle atmosphere from rocket-borne blunt probes

Detailed consideration is given to the determination of electron number densities from conductivity data gathered by rocket-borne blunt probes in the middle atmosphere and to a comparison of these densities with those derived from other diagnostics. A definition of the difficulty of electron density determination using rocket-borne probes is presented. In addition, the procedures for the determination of ion densities from blunt probe data in the middle atmosphere are critically evaluated. General aspects of particle collection using supersonic probes are compared with those of subsonic probes. It is noted that strong (x10) compression regions will form in front of supersonic probes at altitudes up to 100 km and that the altered electron attachment rates could significantly affect indicated electron and negative ion concentrations.