Simultaneous observations of E‐region coherent backscatter and electric field amplitude at F‐region heights with the Millstone Hill UHF Radar

A combined coherent backscatter‐incoherent scatter experiment with the Millstone Hill UHF radar provided simultaneous observations of electric field magnitude and coherent backscatter parameters on the same L shell. A carefully‐designed geometry used sidelobe coherent contamination from two‐stream irregularities at 110 km altitude, appearing at ranges corresponding to F ‐region altitudes in the main beam, in conjunction with simultaneous uncontaminated F ‐region observations of the drift velocity in adjacent range gates. Both logarithmic coherent power and the magnitude of the coherent phase velocity V ph vary linearly with . With the assumption that the coherent phase velocity is approximately the perturbed ion sound speed in the heated E region, we find an excellent agreement between the electron temperature inferred from V ph and previous incoherent‐scatter results relating E ‐region T e to E . A maximum value of ∼3100 K has been found for such wave‐induced E ‐region heating.