E region coherent backscatter at short wavelength and large aspect angle

During a special experiment carried out in June 1987, the European incoherent scatter UHF radar system was operated at an unusually low elevation angle, and detected coherent echoes from the auroral E region at times when the ion drift velocity in the F region was large. This appears to be the first time that coherent echoes have been detected at such a short radar wavelength (0.32 m; frequency 933 MHz) and at such a large angle away from perpendicular to the Earth's magnetic field (up to 6°).