usgs-lidar-dem

Colorize USGS 3DEP DEM tiles by downloading the terrain data, sampling RGB values from ESRI World Imagery, and generating a CRS-tagged LAS file ready for Metashape import. This workflow creates bare-earth ground truth for photogrammetry projects and improves alignment QA across large areas.

Yes, you can colorize a LiDAR DEM LAS file by sampling RGB values from ESRI World Imagery and applying them to the DEM-derived points. This process outputs a colorized, CRS-tagged LAS file suited for Metashape laser-scan imports.

To download USGS 3DEP DEM data and create a LAS file, you need rasterio, laspy, numpy, requests, and Pillow. The optional py3dep library enables programmatic DEM tile downloads within the workflow.

Preparing a colorized LAS file helps with photogrammetry alignment QA by providing surrounding bare-earth ground truth. Importing this CRS-tagged LAS into Metashape extends your photogrammetry project with accurate surrounding terrain data.

The best way to extend photogrammetry terrain using USGS LiDAR data is to automate 3DEP DEM tile discovery, colorize the mosaic with satellite imagery, and import the resulting colored LAS into your active Metashape chunk.

Your Metashape project needs surrounding bare-earth ground truth from USGS LiDAR to improve alignment QA across large areas. Importing a CRS-tagged, satellite-colorized LAS file extends the photogrammetry model with accurate external terrain data.