Hello,
In LAStools, the lasvdatum tool is specifically designed for transforming LiDAR data from ellipsoidal to orthometric elevations, using a grid format typically provided by national surveys. This tool addresses the vertical differences between a geoidal model and an elliptical model of the Earth. By default, the conversion is from ellipsoidal elevations to geoidal (or orthometric) elevations.
For your specific requirement of transforming the vertical datum to NAVD88, you can use lasvdatum with the appropriate geoid grid. If you already have your geoid set to 2012b, you would use a command something like this:
lasvdatum -i in.laz -epsg xxxxx -vgrid g2012bu0.gtx -o out.laz
Get the -epsg code from here
https://epsg.io/ normally in UTM (for example: UTM 12N + WGS 84 ellipsoidal)
This command will take your input file (in.laz), apply the transformation using the g2012bu0.gtx geoid grid (which corresponds to the geoid model you mentioned), and output the transformed file (out.laz).
While las2las and lasheight are also commonly used for various transformations and adjustments in LAStools, lasvdatum is more specialized for vertical datum transformations, especially when dealing with geoid models and converting between ellipsoidal and orthometric elevations.
Finally, I've developed a GPT available at
https://chat.openai.com/g/g-77IlZRj3A-lidar-ai-lastools-helper designed to generate LAStools code for creating batch scripts to process LiDAR data. Additionally, it offers assistance with inquiries about the software, tools, arguments, and general LiDAR-related topics. If you possess an OpenAI GPT Plus subscription, you are welcome to give it a try..
Nelson Mattie, PhD© Remote Sensing
UNIVERSITY OF ALBERTA
Centre for Earth Observation Sciences
Department of Earth & Atmospheric Sciences
2-038 Centennial Centre for Interdisciplinary Science (CCIS)
Edmonton, AB. T6G 2E3. Canada.
Phone:
+1 587.936.1278 | Email:
matt...@ualberta.ca