Basic Terms - Leica FlexLine plus User Manual

7.13.2
Elements of a road
project
Horizontal
geometry elements
FlexLine plus, Programs

Basic Terms

Road projects consist, in general, of a horizontal and a vertical alignment.
a b c
P1'
P1'' P1'''
TSOX_108
For onboard input Road 3D supports the following elements for horizontal alignments.
Element Description
Straight A straight has to be defined by:
• Start point (P1) and end point (P2) with known Easting and Northing
coordinates.
P1
TSOX_109
Curve A circular curve has to be defined by:
• Start point (P1) and end point (P2) with known Easting and Northing
coordinates.
• Radius (R).
• Direction: Clockwise (b) or Anticlockwise (a).
R
R
P2
TSOX_090
Any project point P1 has E, N and H coordinates
in a determined coordinate system and has three
positions.
P1'
P1"
P2'
P1'"
P2''
With a second point P2 the alignment is defined.
P2'''
P1' P2'
P1'' P2''
P1''' P2'''

a
b
c
P2
P1 Start point
P2 End point
P1
a
b
P1 Start point
P2 End point
R
a
b
Position on natural surface
Position on vertical alignment
Position on horizontal alignment
Projection of the alignment onto the
natural surface.
Vertical alignment
Horizontal alignment
Grade angle between the vertical and
horizontal alignment.
Natural surface
Horizontal alignment
Vertical alignment
Radius
Anticlockwise direction
Clockwise direction
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