Evaluation of VLBI Observations with Sensitivity and Robustness Analyses


Küreç Nehbit P. , Heinkelmann R., Schuh H., Glaser S., Lunz S., Mammadaliyev N., ...More

in: Stochastic Models for Geodesy and Geoinformation Science, Frank Neitzel, Editor, MDPI, Basel, pp.91-106, 2021

  • Publication Type: Book Chapter / Chapter Research Book
  • Publication Date: 2021
  • Publisher: MDPI
  • City: Basel
  • Page Numbers: pp.91-106
  • Editors: Frank Neitzel, Editor

Abstract

Very Long Baseline Interferometry (VLBI) plays an indispensable role in the realization of global terrestrial and celestial reference frames and in the determination of the full set of the Earth Orientation Parameters (EOP). The main goal of this research is to assess the quality of the VLBI observations based on the sensitivity and robustness criteria. Sensitivity is defined as the minimum displacement value that can be detected in coordinate unknowns. Robustness describes the deformation strength induced by the maximum undetectable errors with the internal reliability analysis. The location of a VLBI station and the total weights of the observations at the station are most important for the sensitivity analysis. Furthermore, the total observation number of a radio source and the quality of the observations are important for the sensitivity levels of the radio sources. Accordingtotherobustnessanalysisofstationcoordinates,theworstrobustnessvaluesarecausedby atmosphericdelayeffectswithhightemporalandspatialvariability. DuringCONT14,itisdetermined that FORTLEZA, WESTFORD, and TSUKUB32 have robustness values changing between 0.8 and 1.3mm,whicharesignificantlyworseincomparisontotheotherstations. Theradiosources0506-612, NRAO150, and 3C345 have worse sensitivity levels compared to other radio sources. It can be concluded that the sensitivity and robustness analysis are reliable measures to obtain high accuracy VLBI solutions.