Interested in Learning about LiDAR to DEM?
LiDAR (Light Detection and Ranging)is not a new technology...
but it is being deployed in new applications daily. Not long ago Apple integrated the technology into their product. Many of the autonomous vehicles being developed today include LiDAR technology as well. With so many new applications for the technology, I thought it would be helpful to revisit the process of creating a DEM/DTM from LiDAR .
Although uses for LiDAR have grown...
I speak with people who are confused about the process of acquiring data, preparing it for modeling and delivering a usable product for our customers. Gateway gathers LiDAR data by both aerial and terrestrial (ground) means. Although the two process are different the raw data is processed in similar ways depending on your desired product.
- Raw laser data is downloaded from the LiDAR sensor
- GNSS (GPS) control data is downloaded, checked and the projection is corrected
- If an airborne project: laser data is combined with the aircraft's IMU (Internal Measurement Unit) data and adjusted to control
- LiDAR data is adjusted to the corrected projection
- Classification of Raw LiDAR data from the Point Cloud
- Decimation of ground class data to create grid points
- Depending on your needs: Break-line extraction
- DEM - DTM creation
With all of the automation out there...
why is a DEM/DTM not "automatically" generated once the LiDAR data acquisition is complete? Technology has come along way with automatic classification, but as of today there are still processes that need to be completed by trained personnel. At Gateway, we have licensed land surveyors that ensure a customer's data is being projected (placed in the correct spot) on a surface (DEM, DTM). We feel this is one of the areas that can be easily missed. We purchased our first aerial LiDAR unit 6 years ago, with the intent of bringing high quality geo-referenced data to our customers. If you are interested in learning about how Gateway can help you on your next 3D scanning project, please check out our website or call us directly.
