DEVB TC(W) No. 1/2026, Annex A
Fixed-point vs fixed-route LiDAR for the Co-supervision Platform
DEVB TC(W) No. 1/2026, Annex A paragraph 2(i), says the Video of Point Cloud can be produced fixed-point, with LiDAR on poles, tower cranes or other non-movable objects, or fixed-route, with small unmanned aircraft or robots, to minimise blind spots. Kodifly delivers both, ScanStation K4DL-1000 and fixed-route drone LiDAR, planned together for each site.
Two ways to make the same Video of Point Cloud
The Co-supervision Platform (CSP) runs on 4D LiDAR, which DEVB describes as combining time-series imaging with LiDAR point clouds to give dimensional and positioning information at a reasonable level of accuracy for common site usage (Annex A, paragraph 2(i)).
The circular names two ways to produce it. Fixed-point: mount LiDAR devices on fixed poles, tower cranes or non-movable objects. Fixed-route: use small unmanned aircraft (SUAs) or robots on a set route. Both aim to minimise blind spots and provide continuous spatial data.
The circular does not rank one above the other. The choice follows the works. A deep excavation watched for months suits a fixed unit. A long formation area or a building that hides its own far side needs a route. Most sites need both, and the plan should be made once, for the whole works area.
Fixed-point vs fixed-route, side by side
Based on Annex A, paragraph 2(i), of TC(W) No. 1/2026 and Kodifly's two capture approaches.
| Question | Fixed-point | Fixed-route |
|---|---|---|
| Where the LiDAR sits | On fixed poles, tower cranes or other non-movable objects. | Carried by small unmanned aircraft or robots along a set route. |
| What it captures best | One works area watched again and again from the same viewpoint. | Wide or long areas and the faces a fixed unit cannot see. |
| Time series | Continuous, round the clock, from a stable viewpoint. | Repeated passes on the same route, so each pass is comparable. |
| Blind spots | Anything hidden behind structures or outside the line of sight. | Fewer. A route can be planned around the structures that block a fixed view. |
| Typical works | Deep excavation, slopes, rebar decks, MiC installation, tower crane operation. | Site formation, long linear works, roofs and areas between fixed units. |
| Kodifly product | ScanStation K4DL-1000 | Fixed-route drone LiDAR |
| Output on the platform | Colourised point clouds with centimetre-level georeferencing. | Point clouds on the same coordinate frame as the fixed units. |
When to choose fixed-point
Choose fixed-point where the same ground must be watched continuously. The unit stays put, so each scan is taken from the same place and changes stand out when scans are compared. That is the basis of several Annex A, paragraph 5, functions, including the time series point cloud viewer, dimension and volume measurement, slope angle and ground profile measurement, and the MiC and tower crane checks.
ScanStation K4DL-1000 is Kodifly's fixed-point LiDAR. It mounts on poles, tower cranes or other fixed structures, outputs real-time colourised point clouds with centimetre-level georeferencing, has a range accuracy of ±2 cm and sits in an IP65 housing for site conditions.
When to add fixed-route
Add fixed-route capture where a fixed unit cannot see. Structures block line of sight as they rise. Long or spread-out works need too many poles to cover. A drone flown on a set route reaches those areas and returns along the same path, so each pass can be compared with the last and with the fixed-point data.
Kodifly flies fixed-route drone LiDAR on the same coordinate frame as the fixed units. The result is one record of the site on the platform, not two separate data sets.
How Kodifly plans the two together
Map the works and the functions
Start from the works type and the CSP functions in the contract scope, agreed with the project office.
Place the fixed units
Choose poles, tower cranes and other fixed structures with a clear view of the areas that need continuous watching.
Find the blind spots
Check what each fixed view misses, including areas that will be hidden as the structures rise.
Set the drone route
Plan a fixed route that covers the blind spots and the wider works area, on the same coordinate frame.
Install and review
Kodifly engineers install the units, commission the capture and revisit the plan as the site changes.
Fixed-point and fixed-route questions
What is the fixed-point approach in TC(W) No. 1/2026?
It is producing the 4D LiDAR Video of Point Cloud by mounting LiDAR devices on fixed poles, tower cranes or other non-movable objects (Annex A, paragraph 2(i)). Kodifly's fixed-point unit is ScanStation K4DL-1000.
What is the fixed-route approach?
It is producing the Video of Point Cloud with small unmanned aircraft (SUAs) or robots on a set route, designed to minimise blind spots and provide continuous spatial data (Annex A, paragraph 2(i)). Kodifly delivers fixed-route drone LiDAR.
Does the circular require one approach over the other?
No. Annex A, paragraph 2(i), describes both as ways to produce the Video of Point Cloud. The project office defines the CSP scope for the works type, consulting DEVB's Works Policies 4 Section (paragraph 14).
Why use both on one site?
A fixed unit sees one area continuously but cannot see behind structures. A fixed route covers those blind spots and wider areas. Planned together on one coordinate frame, they give one complete record on the platform.
How accurate is ScanStation K4DL-1000?
Kodifly publishes a range accuracy of ±2 cm, real-time colourised point clouds and centimetre-level georeferencing, in an IP65 housing. A full datasheet is available on request.
Is fixed-route drone LiDAR the same as drone progress monitoring under TC(W) No. 9/2025?
They are related but answer different circulars. Drone progress monitoring (HECR-4) requires biweekly 3D photogrammetry models under TC(W) No. 9/2025. Fixed-route drone LiDAR is one way to produce the Video of Point Cloud under TC(W) No. 1/2026. Kodifly delivers both.
Related guides
Plan fixed-point and fixed-route capture
Tell us the site and the works type. We will advise where fixed units and drone routes should cover.