Nowadays, zenith telescope-based digital zenith camera systems (DZCSs), such as the Compact Digital Astronomical Camera (CODIAC) and VErtical by STArs (VESTA), are used to determine highly accurate astrogeodetic deflections of the vertical (DoVs). The CODIAC and VESTA were developed by ETH Zurich and University of Latvia, respectively, and only two CODIAC and four VESTA systems have been produced. The CODIAC system has a proven accuracy higher than 0.05″, while the accuracy of VESTA is ~0.1″. These two DZCSs, which are the most used DZCSs of the last decade, have been used effectively over many survey campaigns. The CODIAC system replaced the DIADEM in the second (Iowa) and third (Colorado) geoid slope validation surveys in the United States. Meanwhile, VESTA has been used for dense DoV measurements in Latvia; these DoVs were used for quasi-geoid determination. In this study, we used both the CODIAC and VESTA to conduct simultaneous observations at the School of Management and Engineering Vaud (HEIG-VD) in Yverdon-les-Bains, Switzerland over five nights in August, 2021. The previous version of the CODIAC, the DIADEM, had been used for simultaneous parallel measurements against the University of Hannover’s DZCS, the TZK2-D. Our DZCS measurements with CODIAC and VESTA mark the second time that simultaneous parallel observations have been made with two different DZCSs. Additionally, the VESTA has never been tested against another DZCS through comparative simultaneous measurements. This comparison between the VESTA and CODIAC systems has allowed for VESTA accuracy validation and checking the agreement between the two DZCSs.

The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)