Grade Check vs Design

The Grade Check tool lets you click points on the map to compare the survey elevation at each location against the design elevation, giving you instant pass, marginal, or fail results based on configurable tolerance bands. It is the primary tool for finished surface quality assurance.

What Grade Check Does

Grade Check compares two values at each point you click:

1. Survey elevation — the height value from the site's DEM (Digital Elevation Model) at that location
2. Design elevation — the height value from the selected design surface at that location

The difference between these two values is then evaluated against your configured tolerance to determine whether the point passes, is marginal, or fails.

Setting Up a Grade Check

Select the Design Surface

Before clicking points, select which design surface to check against. The dropdown lists all design surfaces uploaded to the current site. Choose the surface that represents the target finished level for the area you are inspecting.

Configure Tolerance Bands

Tolerance bands define what constitutes a pass, marginal result, or fail. SiteView provides preset tolerances and a custom option:

💡 Tip

For road subgrade work, a tolerance of plus or minus 50mm is common. For finished pavement or concrete surfaces, tighten it to plus or minus 20mm. Check your project specification for the required tolerance before running the grade check.

Checking Points

With the tool active and a design surface selected, click anywhere on the CesiumJS map where both DEM and design data exist. Each click:

1. Samples the survey elevation from the DEM
2. Samples the design elevation from the design surface
3. Calculates the difference (survey minus design)
4. Evaluates the difference against your tolerance bands
5. Places a colour-coded marker on the map
6. Adds a row to the results table

You can check as many points as needed. Each point is added to the running results.

Map Markers

Markers are colour-coded by result:

• Green — pass (within tolerance)
• Amber — marginal (outside pass tolerance but within marginal threshold)
• Red — fail (outside both tolerance bands)

Markers include a label showing the elevation difference value.

Results Table

The results table in the panel displays one row per checked point:

The table updates in real time as you add points. You can scroll through results if many points have been checked.

ℹ️ Did you know?

If you click a location where either the DEM or the design surface has no data, that point will show as "No Data" rather than a numeric result. This typically means the point is outside the DEM extent or the design surface boundary.

Exporting Grade Check Results

You can export the full results table for use in reports or project records:

• Copy to clipboard — pastes the table data for quick sharing
• Export as CSV — downloads a CSV file with all columns for import into spreadsheets or project documentation. See CSV Export.
• Export as PDF — generates a formatted PDF report with the results table and a map image. See PDF Reports.

Use Case: Finished Surface QA

A typical finished surface quality assurance workflow:

1. Upload the design surface (target finished levels) to the site
2. Fly a drone survey of the completed area
3. Set the tolerance to match the project specification
4. Click a grid of points across the finished surface
5. Review the results — any fails indicate areas that need rework
6. Export the results for the project quality record

⚠️ Watch out!

Grade Check compares against the DEM derived from drone photogrammetry. DEM accuracy depends on ground control, image quality, and processing settings. For high-precision QA (plus or minus 10mm or tighter), consider using RTK surveyed points instead — see Capturing Points.

What's Next?

• Compare to Design Volume — calculate cut and fill volumes against a design surface
• Cross-Section vs Design — visualise profile differences along a section line
• Cut/Fill Heat Map — generate a colour-coded overview of cut and fill across the site
• Grade Check (Measurement Tool) — the standalone grade check tool without a design comparison