The LCS offset that can be specified in an axis LSO is used to describe the offset of a real world object from a position on an axis. This offset is an offset measured in a Local Coordinate System placed at the start offset specified in the LCS. The LCS is a right handed orthogonal three dimensional Cartesian coordinate system.
The orientation of the LCS is depending on the direction of the reference system used by the Axis LSO and on the inclination of the axis at the start offset of the axis LSO.
For reference system offsets that define a point on the axis where the axis is not vertical, the Transversal (T) LSO axis will always be horizontal i.e. parallel to the X, Y plane. For reference system offsets that define a point on the axis where the axis is vertical this approach does not work therefore the orientation of the transversal axis in vertical coordinate systems is defined by the Y - direction of the underlying projected coordinate system. For more details see tables 1 and 2.
Axis |
Description |
Transversal (T) |
The transversal LCS axis is parallel to the X,Y plane of the underlying projected coordinate system. It is orthogonal to the axis direction vector at the start offset of the Axis LSO. Positive values are on the right of the axis when looking in direction of the LSO's reference system. |
Longitudinal (L) |
The longitudinal LCS axis is oriented as the axis at the start offset of the Axis LSO. Positive values are in direction of the LSO's reference system. |
Height (H) |
The height LCS axis is orthogonal to the transversal LCS axis and the longitudinal LCS axis. Positive values are oriented "up", according to the right hand rule. |
Table 1: Orientation of the LCS for positions on the axis where the axis is not vertical
Axis |
Description |
Transversal (T) |
The transversal LCS axis is parallel to the y axis of the underlying projected coordinate system (usually the North direction). Positive values are from axis to the North direction, negative values to the South direction. |
Longitudinal (L) |
The longitudinal LCS axis is oriented as the axis at the start offset of the Axis LSO. Positive values are in direction of the LSO's reference system. |
Height (H) |
The height LCS axis is orthogonal to the Transversal LCS axis and the Longitudinal. Positive values are oriented "up", according to the right hand rule. |
Table 2: Orientation of the LCS for positions on the axis where the axis is vertical
