Accuracy Verification of Superstructure Shape Measurement Using MMS From Under Bridge Where GNSS Radio Wave Reception Is Unstable

Key Points

• The aim is to assess the accuracy of shape measurement of bridge superstructures using MMS in environments with unstable GNSS reception.
• Utilized TLS and MMS for measuring bridge superstructure from below at angles of 45° and 75°.
• Conducted measurements under conditions where GNSS reception was unstable, sometimes resulting in no satellite signals.
• Implemented IMU for correction to improve measurement accuracy.
• Achieved a horizontal RMSE of less than 50mm at verification points despite GNSS instability.
• Measurement accuracy of bridge superstructure dimensions was similar between TLS and MMS.
• MMS demonstrated effective shape measurement capability comparable to TLS under challenging GNSS conditions.