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 (E) over right arrow X (B) over right arrow drift. velocity in adjacent range gates. Both logarithmic coherent power and the magnitude of the coherent phase velocity V-ph vary linearly with \(E) over right arrow\. 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-c to E. A maximum Value of similar to 3100 K has been found for such wave-induced E-region heating.