Investigation of anomalous refraction effect by using automated digital zenith camera VESTA

Project title: Investigation of anomalous refraction effect by using automated digital zenith camera VESTA

Project number: lzp-2024/1-0095

Project implementer: University of Latvia (LU)

Project partners: N/a

Project leader: Inese Vārna

Project implementation lead institution: Faculty of science and technology of University of Latvia

Project period: 01.01.2025. – 31.12.2027.

Project total budget: 300 000 EUR, including LU project part: 300 000 EUR

Expected results:

• statistical characterization of anomalous refraction and recommendations for reducing its impact on digital zenith camera measurements;
• 2 publications in highly cited scientific journals;
• data set of measurements taken during the project implementation.

Scientific group: Inese Vārna, Ansis Zariņš, Augusts Rubans, Ingus Mitrofanovs, Gunārs Silabriedis

The objective of this research work, characterising its novelty, is to explore the behaviour of anomalous refraction (AR) in the Earth's atmosphere by a new approach – using digital zenith camera (DZC) VESTA (VErtical by STArs) and separating AR components from VESTA measurements. AR is the main limiting factor in the accuracy of ground-based astrometric observations causing irregular angular displacements of observed stars. It also affects satellite-related technologies where information passes through the atmosphere in one way or another (as well as remote sensing technologies). Current experience shows that it is observed as an error source in all DZC measurement campaigns. Performing test measurements in various environments will lead to deeper understanding and mitigation of AR phenomenon in zenith.