Figure 4. (a) Computed Quenching coefficient for the 28 pulses and also at the point of the reflection one instant before and after the HF transmitters were turned off. (b)N2 concentration provided by the NRLMSISE-00 (dots) and the ones retrieved using the O(1D) lifetime. (c) Ratio between the N2 retrieved concentrations by the NRLMSISE-00’s concentration for the same altitudes.