LAS Point Statistics As Raster (Data Management)

Summary

Creates a raster whose cell values reflect statistical information about measurements from LAS files referenced by a LAS dataset.

Usage

• The LAS dataset layer can be used to filter LAS points by class code or return values. The layer can be created by using the Make LAS Dataset Layer tool, or by loading the LAS dataset in ArcMap or ArcScene and specifying the desired class codes and return values through the layer properties dialog box.

• LAS points can be classified into a number of categories that describe the material encountered by the lidar return, such as ground, building, or water. The American Society for Photogrammetry and Remote Sensing (ASPRS) defined the following class codes for LAS file versions 1.1, 1.2, and 1.3:

  Classification Value	Classification Type
  0	Never Classified
  1	Unassigned
  2	Ground
  3	Low Vegetation
  4	Medium Vegetation
  5	High Vegetation
  6	Building
  7	Noise
  8	Model Key
  9	Water
  10	Reserved for ASPRS Definition
  11	Reserved for ASPRS Definition
  12	Overlap
  13–31	Reserved for ASPRS Definition

  Note:

  While the LAS 1.0 specifications provide class codes ranging from 0 to 255, it does not have a standardized classification scheme. Any class codes used in 1.0 files would typically be defined by the data vendor and provided through auxiliary information.

• Consider using PREDOMINANT_LAST_RETURN for the Method parameter to identify locations with higher return values that could indicate the presence of vegetation.

• Consider using Z_RANGE for the Method parameter to determine locations with potential outliers.

Syntax

LasPointStatsAsRaster_management (in_las_dataset, out_raster, {method}, {sampling_type}, {sampling_value})

Parameter	Explanation	Data Type
in_las_dataset	The input LAS dataset.	LAS Dataset Layer
out_raster	The location and name of the output raster. When storing a raster dataset in a geodatabase or in a folder such as an Esri Grid, no file extension should be added to the name of the raster dataset. A file extension can be provided to define the raster's format when storing it in a folder: .bil—Esri BIL .bip—Esri BIP .bsq—Esri BSQ .dat—ENVI DAT .img—ERDAS IMAGINE .png—PNG .tif—TIFF If the raster is stored as a TIFF file or in a geodatabase, its raster compression type and quality can be specified using geoprocessing environment settings.	Raster Dataset
method (Optional)	The type of statistics collected about the LAS points in each cell of the output raster. PULSE_COUNT —The number of last return points. POINT_COUNT —The number of points from all returns. PREDOMINANT_LAST_RETURN —The most frequent last return value. PREDOMINANT_CLASS —The most frequent class code. INTENSITY_RANGE —The range of intensity values. Z_RANGE —The range of elevation values.	String
sampling_type (Optional)	Specifies the method used for interpreting the Sampling Value to define the resolution of the output raster. OBSERVATIONS —Defines the number of cells that divide the lengthiest side of the LAS dataset extent. CELLSIZE —Defines the cell size of the output raster. This is the default.	String
sampling_value (Optional)	Specifies the value used in conjunction with the Sampling Type to define the resolution of the output raster.	Double

Code Sample

LasPointStatsAsRaster 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.LasPointStatsAsRaster_3d("test.lasd", "lidar_intensity.img", 
                             "INTENSITY_RANGE", "CELLSIZE", 15)

LasPointStatsAsRaster example 2 (stand-alone script)

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

'''**********************************************************************
Name: LAS Point Statistics As Raster
Description: Identifies the most frequently occurring return value for 
             each pulse in a given set of LAS files. 
             Designed for use as a script tool.
**********************************************************************'''
# Import system modules
import arcpy
import exceptions, sys, traceback

# Set Local Variables
lasD = arcpy.GetParameterAsText(0)
inLas = arcpy.GetParameterAsText(1) #input las files
sr = arcpy.GetParameter(2) #spatial reference of las dataset
statsRaster = arcpy.GetParameterAsText(3)

try:
    arcpy.CheckOutExtension('3D')
    # Execute CreateLasDataset
    arcpy.management.CreateLasDataset(inLas, lasD, 'RECURSION', '', sr)
    # Execute LasPointStatsAsRaster
    arcpy.management.LasPointStatsAsRaster(lasD, statsRaster, 
                                           "PREDOMINANT_RETURNS_PER_PULSE", 
                                           "CELLSIZE", 15)
    arcpy.CheckInExtension('3D')
except arcpy.ExecuteError:
    print arcpy.GetMessages()
except:
    # Get the traceback object
    tb = sys.exc_info()[2]
    tbinfo = traceback.format_tb(tb)[0]
    # Concatenate error information into message string
    pymsg = 'PYTHON ERRORS:\nTraceback info:\n{0}\nError Info:\n{1}'\
          .format(tbinfo, str(sys.exc_info()[1]))
    msgs = 'ArcPy ERRORS:\n {0}\n'.format(arcpy.GetMessages(2))
    # Return python error messages for script tool or Python Window
    arcpy.AddError(pymsg)
    arcpy.AddError(msgs)

Environments

Current Workspace, Extent, Output Coordinate System, Geographic Transformations, Cell Size, Pyramid, Raster Statistics, Output CONFIG Keyword, Auto Commit

Licensing Information

ArcGIS for Desktop Basic: Requires 3D Analyst or Spatial Analyst

ArcGIS for Desktop Standard: Yes

ArcGIS for Desktop Advanced: Yes