Search results for "Geoid"
showing 2 items of 12 documents
Digital zenith camera for vertical deflection determination
2012
Recent accomplishments in advancement of accurate astrometric reference star catalogues, development of digital imaging technology, high accuracy tiltmeter technology, and geocentric coordinate availability provided by GNSS, have made possible accurate, fast and automated determination of vertical deflections using astrometric methods. Zenith cameras for this kind of measurements have been developed or are being developed by several research groups. The paper describes a research project by Institute of Geodesy and Geoinformation, intended to design a portable digital zenith camera for vertical deflection determination with 0.1” expected accuracy. Camera components are described, proposed d…
Performance analysis of Latvian zenith camera
2018
Since finalizing of design in 2016, the digital zenith camera of the University of Latvia was involved in a number of test observations as well as field observations at about 70 different sites. The paper presents analysis of observation results, estimation of instrument’s performance and accuracy. Random and systematic error sources are outlined. Impact of anomalous refraction on vertical deflection determination is discussed. Results of adaptation of GAIA reference star catalog for astrometric data reduction are reported.