Fig. 2From: Measurement of thermospheric temperatures using OMTI Fabry–Perot interferometers with 70-mm etalon a Photograph and b structure of the small-aperture Fabry–Perot interferometer at Darwin, Australia. Dashed lines and a red line show rotation axes of the sky scanner and a path of an incident light, respectively. The scanners A and B rotate 90° in azimuthal direction and ±45° from zenith direction, respectivelyBack to article page