Measurement of thermospheric temperatures using OMTI Fabry–Perot interferometers with 70-mm etalon

Temperatures obtained by the FPIs and comparison with MSIS-E90 and GAIA models. Average temperatures (solid lines) and number of data (dashed lines) obtained at (a) Tromsø, (b) Chiang Mai, (c) Kototabang and (d) Darwin for the shown interval Thick lines show temperatures averaged for every 15 minutes obtained by FP01-04. Data obtained when the airglow intensity was very low (less than 3-sigma of CCD read-out noise) were removed. The error bars indicate standard deviations of the whole data. Thin lines and dotted lines show that obtained by the MSIS-E90 model and the GAIA model, respectively, at an altitude of 250 km.