GPS/GNSS-based 3D grade control systems have made a major impact on how heavy construction is done, but they still have limitations when it comes to achieving very tight vertical accuracies. This is true regardless of which brand you use.
While multi-constellation (GPS, GLONASS, Galileo and more recently Beidou) grade control systems are able to work in more places and under more adverse conditions, these systems are still subject to various orbital errors and environmental factors, which can degrade the vertical accuracy.
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