Measure Tool
:::caution Last revised 2026-05-01 — not re-verified
This page has not been checked against the running system since it was
written, and predates a large part of the current product. It is scheduled
for rewrite. For anything about the API, /docs on a running server is
authoritative.
:::
The Measure Tool lets you measure geodetic distances along a multi-segment line and compute the surface area of a polygon, directly on the Cesium globe.
Opening the tool
Click the ruler icon in the toolbar (between the Histogram and Checkpoint buttons) to open the Measure Tool panel.
Modes
| Mode | What it measures |
|---|---|
| Length | Geodetic distance along a polyline, with per-segment breakdown |
| Area | Surface area of a closed polygon |
Click Length or Area at the top of the panel to switch modes before or during drawing.
Drawing
| Action | Effect |
|---|---|
| Left-click | Add a vertex |
| Double-click | Finish the shape |
| Right-click | Undo the last vertex |
| Click after finishing | Start a new measurement |
A dashed yellow line (Length mode) or filled yellow polygon (Area mode) follows your cursor as you draw, giving a live rubber-band preview. Yellow dots mark each committed vertex.
Results
Length mode
Once two or more points are placed the panel shows:
- Segment breakdown — each segment's geodetic distance (e.g. Seg 1: 234.5 m, Seg 2: 1.234 km). The list appears as soon as there are at least two segments.
- Total length — sum of all segments, updated live as you move the cursor.
Distances are displayed in m below 1 km, km above.
Area mode
Once three or more points are placed the panel shows:
- Total length — perimeter of the polygon.
- Area — surface area of the closed polygon.
Areas are displayed in m² below 10 000 m², ha up to 1 km², km² above.
Controls
| Button | Action |
|---|---|
| Length | Switch to line-distance mode |
| Area | Switch to polygon-area mode |
| Clear | Remove all vertices and results, restart the tool |
The Clear button is enabled only after a measurement has been finished (double-click).
Collapsing the panel
Click the Measure Tool section title to collapse or expand the panel while keeping the tool active. The open/closed state is saved across sessions.
Closing the tool
Click the toolbar ruler icon again to close the panel and remove all drawn entities from the map.