Rocket and incoherent scatter radar common‐volume electron measurements of the equatorial lower ionosphere

[1] A coordinated rocket and radar investigation has enabled the comparison of electron density measurements in essentially a common volume of the equatorial lower ionosphere. The rocket instrumentation included a Faraday rotation experiment, uniquely adapted for measuring electrons at low latitude, and fixed-bias Langmuir probes. The ALTAIR tracking radar was configured in an incoherent scatter mode. For the 75–92 km region, we note very good agreement between Faraday rotation and radar electron density measurements. Langmuir probe current measurements, calibrated to the Faraday rotation data, provided information about fine-scale electron density vertical structure and extended the rocket-radar comparisons of electron density to 130 km. Good overall agreement was also observed at higher altitudes, with evidence of electron density layering - including sporadic E - detected by both measurement techniques. The outcomes from our study support this unique Faraday rotation approach and the IS radar for measuring electron density in the equatorial lower ionosphere.