Astrogeodetic Deflection of the Vertical at ETH Zürich: From the Development of Instrumentations to Concrete Applications.

Abstract:

Since 30 years, the Geodesy and Geodynamics laboratory of ETH Zurich is developing astrogeodetic instrumentations in order to determine astronomical deflections of the vertical (DoV). Thanks to this long and continuously accumulated experience and fruitful collaborations, two new operational systems designed for unexperienced operators are now available. The first one, CODIAC (COmpact DIgital Astrometric Camera), is a new very portable zenith camera which can be used for a highly precise (<0.1 arcsec in 20 min) determination of DoV. The second one, QDaedalus is a low-cost system which can be clipped on traditional total stations thus permitting the determination of DoV and/or astronomical azimuths. This system allows fully automatic observations with a precision of 0.3-0.4 arcsec within 20 min acquisition time. Both systems will be presented in terms of performance and in relation to ongoing projects for local geoid determination and validation in the USA and at CERN (European Laboratory for Particle Physics) in Switzerland/France.