Artificial airglow For experimental work on HF induced artificial airglow, ALIS is an invaluable instrument, in that the sensitivity and signal-to-noise ratio of the current detectors lead to unmatched quality in the observations. The multi-station configuration further allows the possibility of retrieving the three-dimensional distribution of emissions with a time resolution of 10 (proven) to 5 (possible) s. Together with the EISCAT Heating and EISCAT UHF this opens up mind-breaking opportunities for experiments: Study HF-pumping at gyro-harmonic frequency, giving a direct answer as to which process (Langmuir turbulence or upper hybrid turbulence) is dominant in producing the $O(^1D)$ excitation. Measure the ratio between the red and green emissions to bring clarity to the character of the electron distribution. This should be done with varying radiative power to investigate the intensity response to the radiated effect in both wavelengths. Make measurements of enhanced airglow with all stations simultaneously in order to improve the quality and validity of the volume emission distribution estimate. Study the transition from the initially speckled airglow distribution to the ``simpler'' steady state distribution. This should be accomplished by varying the radiative effect. Investigate the relation between dynasond and EISCAT UHF measurements of convection, FPI measurements of the neutral wind with the drift of the airglow clouds and the neutral wind estimates,. The current 3D modelling of the 6300 Å airglow gives atmospheric parameters such as neutral wind, Determine the relation between the antenna pattern of the EISCAT Heating beam and the shape of the $O(^1D)$ excitation rate distribution. Test the altitude variation of the effective lifetime of $O(^1D)$, which could be an efficient way of measuring the altitude variation in neutral density, and could possibly resolve the question about which quenching reactions are important for $O(^1D)$. This can be achieved by measuring the decay of artificial airglow for several HF-pulses while the FH-plasma interaction increases due to the decaying electron concentration in the F-region. Search for the wide peaks at 1 MHz offset from the ion line in the EISCAT VHF spectrum that are are predicted in paper V.. This spectral shape is a consequence of the electron neutral interaction. It is possible to measure the magnitude of this effect.