Installation and commissioning of an in-house developed table-top Fabry-Perot interferometer and the quality of data recorded from it - a system that is made in India

Abstract

We present the design, indigenous development, and commissioning of a compact table-top Fabry-Perot interferometer (FPI) for high-resolution airglow observations. The system was initially tested at the Centre for Research and Education in Science and Technology (CREST) in Hosakote and subsequently commissioned at the Vainu Bappu Observatory (VBO) in Kavalur, southern India. We report initial campaign data revealing high-quality interference fringes captured throughout the night when the airglow intensity was strong. The acquired images demonstrate outstanding brightness and contrast, with no detectable ghosting artefacts, achieving high signal-to-noise ratios even with exposure times as short as 10–15 minutes during peak airglow activity. While the observed shifts in peak positions for the cardinal azimuth directions indicate the presence of line-of-sight thermospheric winds, the precise determination of these wind speeds will require rigorous analysis of thermal and environmental corrections for any possible wavelength drift of the etalon during the night.