Cross-Section Measurement

The Cross-Section tool lets you draw a line across the terrain and see a detailed cross-section profile. The interactive SVG chart shows the survey surface, and if a design surface is loaded, it overlays the design profile with cut/fill shading — making it easy to see where the ground is above or below the intended design level.

Activating the Tool

Open the Measurements tab in the site detail floating panel and click the Cross-Section icon, or press X on your keyboard. The cursor changes to a crosshair.

ℹ️ Did you know?

The Cross-Section tool works with or without a DEM. If a DEM is available, the survey profile is sampled from the DEM for high accuracy. If no DEM is available, the world terrain dataset provides an approximate profile. A design surface is optional — without one, the chart shows only the survey profile.

Drawing the Section Line

Click on the map to draw the cross-section line:

1. First click — places the left side of the section (shown on the left of the chart)
2. Second click — places the right side of the section and generates the cross-section chart

The width of the section is determined by the distance between the two points. Draw the line perpendicular to the feature you are examining — for example, across a road, through a trench, or over an embankment.

💡 Tip

For road cross-sections, draw the line perpendicular to the road centreline from one side of the formation to the other. For trench profiles, draw across the trench from undisturbed ground on one side to undisturbed ground on the other, so you can see the full excavation shape in context.

Survey-Only Profile

When no design surface is loaded, the chart shows a single profile line representing the current ground surface:

• Survey profile line — a continuous line showing the terrain elevation along the section, sampled from the DEM (or world terrain if no DEM is available)
• Shaded area — the region beneath the profile is lightly shaded to give visual weight to the terrain shape
• Vertical axis — elevation in metres
• Horizontal axis — distance along the section from left to right

This mode is useful for understanding terrain shape, verifying excavation profiles, and checking natural ground conditions.

Design Surface Overlay

When a design surface is loaded for the site, the chart shows both profiles with cut/fill shading:

Dual Profile Lines

• Survey profile — the current ground surface from the DEM, drawn in blue
• Design profile — the intended design surface, drawn in grey

Cut/Fill Shading

The areas between the two profiles are colour-coded:

The shading makes it immediately obvious where the ground is high (cut required) and where it is low (fill required) relative to the design.

ℹ️ Did you know?

The cut/fill shading in the cross-section is a 2D representation. For volumetric cut/fill quantities within a defined boundary, use the Volume & Stockpile tool with the "Compare to Design Surface" reference mode.

Interactive Chart Features

The cross-section chart is interactive:

• Hover crosshair — move your mouse across the chart to see the exact elevation and distance at any point. If a design surface is loaded, both the survey and design elevations are shown
• Map synchronisation — as you hover on the chart, a marker moves along the section line on the 3D globe, showing you the corresponding point on the ground
• Zoom — scroll or pinch to zoom into specific sections of the chart for more detail

Practical Uses

• Earthworks progress — draw sections across an earthworks area to visually check how the current ground compares to the design
• Trench and excavation profiles — see the shape of trenches, foundation excavations, and cuttings in cross-section
• Road formation — verify that the road cross-section shape matches the design, including crossfall, shoulders, and batters
• Embankment profiles — check the shape and dimensions of embankments, dams, and levees
• Drainage channels — see the profile of drainage channels and verify their shape against the design

💡 Tip

Take cross-sections at regular intervals along the length of an earthworks area. Saving each section with chainage references in the notes creates a set of profiles that document the progress of the works across the site. This is valuable for progress claims and as-built records.

Section Width and Resolution

The width of the cross-section is determined by the length of the line you draw. SiteView samples the DEM at regular intervals along the section line, with the sampling density based on the DEM resolution:

• Short section lines (e.g., 20 metres across a trench) produce high-detail profiles
• Long section lines (e.g., 500 metres across a valley) produce broader profiles showing larger-scale terrain features

For detailed examination of specific features, draw shorter section lines that focus on the area of interest.

⚠️ Watch out!

If the section line extends outside the bounds of your processed DEM, the portion outside the DEM falls back to world terrain data. This can create a visible step in the profile where the data source changes. Keep your section lines within the DEM coverage area for consistent accuracy.

Saving the Measurement

Click Save to record the cross-section. The saved record includes the section line geometry, the survey profile data, and (if applicable) the design profile and cut/fill data. Add a category, notes (such as the chainage or grid reference of the section), and photos. Saved cross-sections appear in the Measurements tab and can be recalled with their full chart.

What's Next?

• Elevation Profile — generate a longitudinal elevation profile along a drawn line
• Grade Check — compare spot elevations at multiple points against the design
• Measurement Tools Overview — return to the full list of measurement tools