Abstract: In order to derive the temperature in the mesopause region from hydroxyl (OH*) airglow, in which intensities of three lines of OH* emission and a basic position are measured during the night using ground-based IR spectrometers, a noisy OH* spectrum is smoothed by filtering out white noise superimposed on the measured OH* intensities, by means of a spectral analysis method in the form of a harmonic analysis and by means of adaptation using the Voigt function which is carried out in the form of a combination of a Lorentz distribution and a Doppler distribution. A decision is made on the quality of the adaptation of the smoothed spectrum obtained to the original spectrum using statistical characteristic variables and by selecting one of the two methods, harmonic analysis function or Voigt function, and the temperature is thus accurately determined.

Abstract: In order to derive the temperature in the mesopause region from hydroxyl (OH*) airglow, in which intensities of three lines of OH* emission and a basic position are measured during the night using ground-based IR spectrometers, a noisy OH* spectrum is smoothed by filtering out white noise superimposed on the measured OH* intensities, by means of a spectral analysis method in the form of a harmonic analysis and by means of adaptation using the Voigt function which is carried out in the form of a combination of a Lorentz distribution and a Doppler distribution. A decision is made on the quality of the adaptation of the smoothed spectrum obtained to the original spectrum using statistical characteristic variables and by selecting one of the two methods, harmonic analysis function or Voigt function, and the temperature is thus accurately determined.

Abstract: For the detection of geotectonic signals triggered by a geotectonic event, an infrasonic wave accompanying the geotectonic event and being generated at the ground and temperature fluctuations are utilized, causing a modulation of an airglow. The modulation of the airglow is detected from the ground by means of an infrared spectrometer and the mesopause temperature is measured with a high temporal resolution. For the detection of a geostationary event, a number of simultaneously operated infrared spectrometers is provided in regions sensitive to geotectonic events.