-As the clocks and orbits coming from real-time GNSS engine are expected to be in the 'IGS05' reference system (X,Y,Z, ECEF), no transformation is carried out if this option is selected. -
--The implemented formulas for transformation from ITRS (IGS05) to ETRS89 are taken from 'Boucher and Altamimi 2007: Specifications for reference frame fixing in the analysis of EUREF GPS campaign', see http://etrs89.ensg.ign.fr/memo2007.pdf. The following Helmert transformation parameters have been introduced from there: +Concerning 'IGS05'; +As the clocks and orbits coming from real-time GNSS engine are expected to be in the 'IGS05' system, no transformation is carried out if this option is selected. +
++Concerning 'ETRS89'; +From the complete transformation chain 'IGS05->ITRF2005->ITRF2000->ETRS89' only the transformation 'ITRF2000->ETRS89' has been implemented. The formulas for that are taken from 'Boucher and Altamimi 2007: Specifications for reference frame fixing in the analysis of EUREF GPS campaign', see http://etrs89.ensg.ign.fr/memo2007.pdf. The following 6 Helmert transformation parameters were introduced:
-Translation in X: 0.056 m -Translation in Y: 0.048 m -Translation in Z: -0.037 m -Rotation in X: 0.054 mas/y -Rotation in Y: 0.518 mas/y -Rotation in Z: -0.781 mas/y +Translation in X: 0.054 m +Translation in Y: 0.051 m +Translation in Z: -0.048 m +Rotation in X: 0.081 mas/y +Rotation in Y: 0.490 mas/y +Rotation in Z: -0.792 mas/y+
+Note that the neglect of transformations 'IGS05->ITRF2005->ITRF2000' in BNS may lead to discrepancies up to 2 centimenters. +