Is it possible to merge two mobile scanning passes (trolley with IMU) with scale adjustment in CloudCompare?

[max1985]

Hello everyone,

I have two separate mobile scans collected with an Amberg trolley equipped with IMU and ZF 9012.
Each run was processed independently, and now I would like to merge both point clouds into a single cloud.

The scans align best at the fixpoints, but in the sections between the fixpoints, there is a visible drift and mismatch between the clouds — typical for IMU-based systems.
Therefore I would need a scale or stretching option along the trajectory to compensate for the IMU drift.

I know that Cyclone only supports best-fit (rigid) transformations, without any scaling.

My question is:
Is there any way in CloudCompare to perform a cloud-to-cloud alignment that includes scaling (similar to a 7-parameter Helmert transform)?

Any advice or experience with similar Amberg or mobile datasets would be greatly appreciated!

[daniel]

Well, you can use the 'adjust scale' option both in the ICP and point-pair based alignment tools. But that's not along a particular direction, but maybe that's sufficient.