Hi Qixing,
DTM=Digital Terrain Model, ground points only.
DSM=Digital Surface Model, ground + bushes + trees + buildings, etc...
Dave
Dave Stoll
Las Vegas, Nevada
64GB DDR4 2400MHz ECC SoDIMM / 1TB SSD
NVIDIA Quadro P5000 16GB
Windows 10 Pro 64 / Civil 3D 2024