Comparisons of equatorial irregularities measurements from C/NOFS: TEC using CERTO and CITRIS with in-situ plasma density



[1] Equatorial plasma density measurements using two techniques are analyzed. The unique instrument complement on C/NOFS (Communication/Navigations Outages Forecasting System) allows for the measurement of TEC (Total Electron Content) using the CERTO (Coherent Electromagnetic Radio TOmography) beacon and measurement of in-situ densities using the PLP (Planar Langmuir Probe). In a nearby orbit, the CITRIS (sCIntilation and TEC Receiver In Space) was available for complementary measurements. TEC was measured with 1) CERTO-CITRIS conjunctions that allow estimates of absolute TEC and 2) CITRIS with ground-based DORIS (Doppler Orbitography and Radiopositioning Integrated by Satellite) beacons. The combination of the remote and in-situ techniques provides more information, enhanced believability for probe measurements as the satellite transitions from darkness to sunlight, as well as cross-calibration and better accuracy for both data sets. The measurements presented are taken in unusually quiet geomagnetic conditions and indicate equatorial irregularities are present nearly 80% of the time for nighttime measurements.