TerraScan User Guide

Deduce scanner positions

Deduce scanner positions command creates trajectory information for tripod mounted scanner data where:

•each scan has its own line number in the point cloud. The line information is used to separate one scanner position from another.

•scanner appears as a circular void area without points. The software assumes that the scanner is located in the center of the void area.

The routine computes the average XY position of points in one line and then searches for the void area. It creates a trajectory file with one position. The process may fail if a scanner position is close to a wall or if the void area is not circular.

You can use this method, if no text file for scanner positions is available for import.

The deduced trajectory allows processes for the point clouds that rely on trajectory information, such as cut overlap, classify by range, compute normal vectors towards the direction of scanner, etc..

To deduce scanner positions:

1. Set a directory for storing trajectories.

2. Load the point cloud produced by the scanner. You may load point clouds from several scanner positions.

3. Select Deduce scanner positions from the File pulldown menu.

The Deduce Scanner Positions dialog opens:

4. Define settings and click OK.

This writes the scanner positions as TerraScan trajectory binary file(s) into the active trajectory directory. The name of a file is determined by the line number.