Think converting WGS84 positions to ETRS89 today will produce the same result you obtained a few years ago ? It won’t: #ETRS89 takes the tectonic drift of continental #Europe into account so the conversion is time-dependant. About 25 milimeters a year adds up fast - the divergence between the two systems already reaches about 60 centimeters... Avoid #WGS84 for survey-grade positioning ! ▻http://www.killetsoft.de/t_1009_e.htm #geography #positioning #GPS #tectonique