I downloaded about 9 LiDAR scenes from USGS and I want to use ArcGIS to merge them so that I can carry out tasks on them together as opposed to one by one.
For some tasks, it is usually better working with tiles (and batch process them) rather than a full merged file so to use memory efficiently.
On the other hand, some tasks will require all tiles to be processed altogether so to avoid 'edge artifacts' (like creating a DEM). In this case, two options are:
- i) work with tiles using tools that can process them on-the-fly.
In ArcGIS, create a LAS Dataset and work form there. For example: Converting LiDAR data to raster (DEM/DSM) for ArcGIS input?.
- ii) work on a full merged file.
Many software for LiDAR point cloud processing can merge files. One of them is Fusion, which is free.
MergeData tool does what you want.
MergeData combines several point cloud files into a single output file.
MergeData *.las alldata_merged.las
C:\Fusion\MergeData C:\lidar_data\*.las C:\lidar_data\output\alldata_merged.las
This will merge all .las files in directory
C:\lidar_data, and will create a merged file named
alldata_merged.las in the subfolder
Another option is larmerge from LAStools. See: Merging more than 9 input files with lasmerge?. LAStools can also merge files on-the-fly; take a look at examples from las2dem (search the switch
Still about LAStools, one can also use buffered tiles (also to avoid 'edge artifacts') while speeding up processing through parallel core usage.