Merge LiDAR Point Clouds Online

The LiDAR merging challenge

A LiDAR survey rarely produces a single file. Depending on the sensor type and acquisition protocol, you end up with multiple point clouds that need to be assembled:

• Mobile LiDAR (MMS, SLAM): each session or pass generates a separate file. A survey of an underground network over several hundred meters can produce a dozen LAS files.
• Drone-mounted LiDAR: successive flights or processing batches from Pix4D, LiDAR360, or DJI Terra produce separate tiles or blocks.
• Fixed terrestrial scanner: each station produces one scan "bubble". Assembling all stations into a single global cloud is a mandatory processing step.

In all these cases, merging is not straightforward if the files don't share the same coordinate reference system — which is common when data comes from different sensors or separate projects.

Typical use cases

How to merge LiDAR point clouds with GeoRef Cloud

1. Upload your LAS or LAZ files to GeoRef Cloud — multiple files at once
2. Enter or confirm the source coordinate system (EPSG code) for each file. GeoRef Cloud auto-detects the CRS if it is embedded in the LAS header.
3. If files use different CRS, select a common target system (e.g. EPSG:32632 UTM zone 32N, EPSG:2154 Lambert 93, EPSG:2056 CH1903+…)
4. Add GCP points if precise georeferencing is required
5. Run the merge — GeoRef Cloud reprojects and combines all clouds into a single file
6. Download the final LAS or LAZ file, ready for QGIS, CloudCompare, Autodesk ReCap, or your preferred software

Supported coordinate systems

GeoRef Cloud supports all EPSG codes recognized by the PROJ/EPSG database. Commonly used CRS for LiDAR projects in Europe:

• EPSG:2154 — RGF93 / Lambert-93 (French national projection)
• EPSG:3942–3950 — RGF93 / CC42 to CC50 (French conformal conic zones)
• EPSG:32630–32632 — WGS84 / UTM zones 30N, 31N, 32N
• EPSG:4326 — WGS84 geographic (latitude/longitude)
• EPSG:2056 — CH1903+ / LV95 (Swiss coordinate system)
• All other valid EPSG codes recognized by PROJ

Frequently asked questions

My LAS files have no CRS in the header — what should I do?

This is common with certain mobile scanners or software exports. In GeoRef Cloud, you can manually enter the source EPSG code for each file. The application will then guide you through reprojection and merging.

Is point classification preserved after merging?

Yes. Standard LAS attributes are preserved in the output file: classification (ground, vegetation, building, unclassified…), intensity, RGB color, return number, and GPS time.

Can I merge files with very different point densities?

Yes. GeoRef Cloud handles files with different densities and sizes. The merged output contains all points from the source clouds, without automatic subsampling.

What is the difference between merging and registration?

Registration involves geometrically aligning two overlapping point clouds by minimizing the distance between corresponding points — this is what ICP (Iterative Closest Point) does in CloudCompare. Merging is the subsequent step of combining the registered clouds into a single file. GeoRef Cloud focuses on the merge step with CRS reprojection, assuming the point clouds are already correctly aligned or share the same geodetic reference frame.

Is the output compatible with QGIS and AutoCAD?

Yes. LAS/LAZ format is natively supported by QGIS (via the Point Cloud plugin), CloudCompare, Autodesk ReCap, Leica Cyclone, and most geomatics and surveying software.

Can I merge LiDAR clouds from different UTM zones?

Yes. If your files span two UTM zones (e.g. 31N and 32N), you can reproject both to a common CRS before merging. GeoRef Cloud supports all valid EPSG transformations via the PROJ library.

Why use GeoRef Cloud instead of a local tool?

Tools like CloudCompare, LAStools, or PDAL are powerful and free — but they require local installation, command-line knowledge for PDAL, and a learning curve. GeoRef Cloud is designed for field operators and surveyors who want clean results quickly, without becoming system administrators.

The other key advantage: GeoRef Cloud combines GCP georeferencing, CRS transformation, and point cloud merging in a single interface — operations that would otherwise require three separate tools chained manually.