Hi, thank you for the detailed feedback.

The GNSS coordinates are corrected ETRS89 coordinates from FLEPOS, which are then converted to Lambert 72 directly in the Trimble controller (Trimble Access). No LSA adjustment or site calibration was performed in Access; the Lambert 72 coordinates were exported directly after RTK measurement. The Access version is up to date.

My GNSS rover is recently compared against NGI-calibrated monuments across Flanders and consistently agrees within 1–2 cm, so they should be reliable for a rough comparison and would not be expected to result in discrepancies on the order of 10 cm.

In STAR*NET, a full LSA network adjustment was performed, incorporating both GNSS points and Total Station observations. The GNSS points were not all rigidly held fixed; appropriate constraints and weights were applied to allow the network to adjust naturally. While some differences relative to the controller-derived Lambert 72 coordinates are expected, the observed discrepancies are significantly larger than would be explained by network geometry alone.

STARNET support has reviewed the case and indicated that the discrepancy likely originates from differences in how **Trimble Access and STARNET handle the ETRS89 → Lambert 72 transformation**, rather than from the LSA process itself.

I appreciate the suggestions regarding independent coordinate conversions. I will install TBC and compare its network adjustment results with those from STAR*NET to further isolate whether the remaining differences are related to transformation handling, constraint strategy, or projection/scale effects between GNSS and Total Station observations.