A Performance Analysis of the Leica MS60 MultiStation-Based QDaedalus Astrogeodetic Measurement System at the HEIG-VD Test Station, Switzerland

Since 2014, total station-based QDaedalus astrogeodetic measurement systems have been used to observe astronomical latitudes and longitudes to determine the astrogeodetic deflection of the vertical (DoV). In this study, the Leica Nova MS60 MultiStation-based QDaedalus system’s precision was determined at the HEIG-VD test station, located on the university campus in Yverdon-les-Bains, Switzerland. The data were collected over 13 nights (in an observation period of 44 days from February-April 2021), and comprise 115 series of observations performed over 26 sessions. The term “series” here describes the DoV data obtained during a specified period; QDaedalus observations were executed at ~15 minutes per series, and up to seven series of observations were conducted per session. The standard deviations (SDs) were calculated as 0.11″ and 0.09″ for the N-S and E-W components of the DoV, respectively. The SDs of the results from the HEIG-VD test station show that the N-S DoV components are not as precise as the E-W DoV components. There is a systematic trend in the observed N-S DoV data; the spread of the data in the N-S direction (0.92″) is larger than in the E-W direction (0.71″). The large trend in the N-S direction may be explained by the 0.008″/day trend (0.38″ over the 44-day observation period) in the N-S DoV components; however, this will require further investigation.

This study is the most extensive thus far for determining the precision of the QDaedalus astrogeodetic measurement system. We can conclude that the precisions of the two components lie on the same order of magnitude of 0.1″. These results and the applied method show that the MS60-based QDaedalus system is at least as reliable as the previously-reported total station-based QDaedalus systems. As a result, the MS60-based QDaedalus system can be used effectively in astrogeodetic applications that require high precision. Also, this study demonstrates that astrogeodetic test observations can be conducted at the HEIG-VD test station to determine the precision of newly installed QDaedalus systems.