Create LAS Dataset—Help

Summary
Illustration
Usage
Syntax
Code sample
Environments
Licensing information

Summary

Creates a LAS dataset referencing one or more LAS files and optional surface constraint features.

Illustration

Usage

The LAS dataset is designed for use with lidar data in the .las or .zlas formats. LAS file versions 1.0–1.4 are supported. Esri's EzLAS Optimizer is a stand-alone lidar utility that can be used to generate .zlas files or convert them back to the .las format.
Each LAS file is examined to determine if its internal structure is consistent with the LAS specifications. If any LAS file fails to load into the LAS dataset, this may indicate the file is corrupted or has erroneous information in its header. Consider using Esri's CheckLAS utility to determine if some commonly encountered issues may exist in your data.
Surface constraint features can be used to enforce feature-derived elevation values that represent surface characteristics in the LAS dataset.
Each LAS file typically contains spatial reference information in its header which is read by the LAS dataset. If this information is missing or improperly defined, the LAS file will not be placed in its correct location. If the correct spatial reference is known, consider using the Create PRJ For LAS parameter to create a .prj file that properly georeferences the lidar data. The .prj file will share the LAS file's name, reside in the same folder, and contain the well-known text representation of the LAS file's coordinate system, similar to the .prj file associated with a shapefile.

The LAS format supports the classification of each point based on the specifications defined by the American Society for Photogrammetry and Remote Sensing (ASPRS). The ArcGIS platform applies the classification scheme specified for LAS file version 1.4:


Classification Value	Classification Type
0	Never Classified
1	Unassigned
2	Ground
3	Low Vegetation
4	Medium Vegetation
5	High Vegetation
6	Building
7	Low Noise
8	Model Key / Reserved
9	Water
10	Rail
11	Road Surface
12	Overlap / Reserved
13	Wire – Guard
14	Wire – Conductor
15	Transmission Tower
16	Wire – Connector
17	Bridge Deck
18	High Noise
19 – 63	Reserved for ASPRS Definition (LAS 1.1 to 1.3 support up to class code 31)
32 – 255	User Definable (Only supported in LAS 1.0 and certain versions of 1.4)

In the tool dialog window, a folder can also be specified as an input by selecting the desired folder in Windows Explorer and dragging it into the parameter's input box.

Syntax

CreateLasDataset(input, out_las_dataset, {folder_recursion}, {in_surface_constraints}, {spatial_reference}, {compute_stats}, {relative_paths}, create_las_prj)

Parameter	Explanation	Data Type
input [input,...]	The LAS files and folders containing LAS files that will be referenced by the LAS dataset. This information can be supplied as a string containing all the input data or a list of strings containing specific data elements (for example, "lidar1.las; lidar2.las; folder1; folder2" or ["lidar1.las", "lidar2.las", "folder1", "folder2"]). See Understanding tool syntax for more information on specifying lists for input.	File; Folder
out_las_dataset	The LAS dataset that will be created.	LAS Dataset
folder_recursion (Optional)	Specifies whether lidar data residing in the subdirectories of an input folder will be added to the LAS dataset. NO_RECURSION —Only lidar files found in an input folder will be added to the LAS dataset. This is the default. RECURSION —All LAS files residing in the subdirectories of an input folder will be added to the LAS dataset.	Boolean
in_surface_constraints [[in_feature_class, height_field, SF_type],...] (Optional)	The features that will be referenced by the LAS dataset when generating a triangulated surface. Each feature will need the following properties defined: in_feature_class—The feature to be referenced by the LAS dataset. height_field—Any numeric field in the feature's attribute table can be used to define the height source. If the feature's geometry contains z-values, it can be selected by specifying Shape.Z. If no height is desired, specify the keyword <None> to create Z-less features whose elevation would be interpolated from the surface. SF_type—The surface feature type that defines how the feature geometry gets incorporated into the triangulation for the surface. Options with hard or soft designation refer to whether the feature edges represent distinct breaks in slope or a gradual change. anchorpoints—Elevation points that never get thinned away. This option is only available for single-point feature geometry. hardline or softline—Breaklines that enforce a height value. hardclip or softclip—Polygon dataset that defines the boundary of the LAS dataset. harderase or softerase—Polygon dataset that defines holes in the LAS dataset. hardreplace or softreplace—Polygon dataset that defines areas of constant height.	Value Table
spatial_reference (Optional)	The spatial reference of the LAS dataset. If no spatial reference is explicitly assigned, the LAS dataset will use the coordinate system of the first input LAS file. If the input files do not contain any spatial reference information and the Input Coordinate System is not set, then the LAS dataset's coordinate system will be listed as unknown.	Coordinate System
compute_stats (Optional)	Specifies whether statistics for the LAS files will be computed and a spatial index generated for the LAS dataset. The presence of statistics allows the LAS dataset layer's filtering and symbology options to only show LAS attribute values that exist in the LAS files. A .lasx auxiliary file is created for each LAS file. COMPUTE_STATS —Statistics will be computed. NO_COMPUTE_STATS —Statistics will not be computed. This is the default.	Boolean
relative_paths (Optional)	Specifies whether lidar files and surface constraint features will be referenced by the LAS dataset through relative or absolute paths. Using relative paths may be convenient for cases where the LAS dataset and its associated data will be relocated in the file system using the same relative location to one another. ABSOLUTE_PATHS —Absolute paths will be used for the data referenced by the LAS dataset. This is the default. RELATIVE_PATHS —Relative paths will be used for the data referenced by the LAS dataset.	Boolean
create_las_prj	Specifies whether .prj files will be created for the LAS files referenced by the LAS dataset. NO_FILES —No files will have a PRJ file created. This is the default. FILES_MISSING_PROJECTION —Only LAS files without a spatial reference will have a corresponding PRJ file. ALL_FILES —All LAS files will have a corresponding PRJ file.	String

Code sample

CreateLasDataset example 1 (Python window)

The following sample demonstrates the use of this tool in the Python window.

import arcpy
from arcpy import env

env.workspace = "C:/data"
arcpy.CreateLasDataset_management("folder_a; folder_b/5S4E.las", 
                                "test.lasd", "RECURSION",
                                "LA/boundary.shp <None> Softclip;"\
                                "LA/ridges.shp Elevation hardline", "", 
                                "COMPUTE_STATS", "RELATIVE_PATHS")

CreateLasDataset example 2 (stand-alone script)

The following sample demonstrates the use of this tool in a stand-alone Python script.

'''*********************************************************************
Name: Export Elevation Raster from Ground LAS Measurements
Description: This script demonstrates how to export
             ground measurements from LAS files to a raster using a 
             LAS dataset. This sample is designed to be used as a script
             tool.
*********************************************************************'''
# Import system modules
import arcpy

try:
    # Set Local Variables
    inLas = arcpy.GetParameterAsText(0)
    recursion = arcpy.GetParameterAsText(1)
    surfCons = arcpy.GetParameterAsText(2)
    classCode = arcpy.GetParameterAsText(3)
    returnValue = arcpy.GetParameterAsText(4)
    spatialRef = arcpy.GetParameterAsText(5)
    lasD = arcpy.GetParameterAsText(6)
    outRaster = arcpy.GetParameterAsText(7)
    cellSize = arcpy.GetParameter(8)
    zFactor = arcpy.GetParameter(9)
    if arcpy.ProductInfo == 'ArcView':
        arcpy.CheckOutExtension('3D')
    # Execute CreateLasDataset
    arcpy.management.CreateLasDataset(inLas, lasD, recursion, surfCons, sr)
    # Execute MakeLasDatasetLayer
    lasLyr = arcpy.CreateUniqueName('Baltimore')
    arcpy.management.MakeLasDatasetLayer(lasD, lasLyr, classCode, returnValue)
    # Execute LasDatasetToRaster
    arcpy.conversion.LasDatasetToRaster(lasLyr, outRaster, 'ELEVATION',
                              'TRIANGULATION LINEAR WINDOW_SIZE 10', 'FLOAT',
                              'CELLSIZE', cellSize, zFactor)
    arcpy.GetMessages()
    
except arcpy.ExecuteError:
    print(arcpy.GetMessages())
    
except Exception as err:
    print(err.args[0])
    
finally:
    arcpy.management.Delete(lasLyr)

Environments

Licensing information

Basic: Requires 3D Analyst or Spatial Analyst
Standard: Yes
Advanced: Yes

ArcMap

Create LAS Dataset