Create a Raster using LiDAR LAS

  1. On the Raster ribbon tab, in the Interpolation group, expand Create Raster.
  2. Select the interpolation method from:
    • LiDAR LAS

    The Create Raster - LiDAR LAS panel displays.

  3. Browse for and select the Input LAS folders.
  4. Browse for and select the Input LAS files.
  5. Select the LAS spatial reference.
  6. Select the LAS classification filter.
  7. Select the Fields to interpolate.
  8. Name the Output raster.
  9. Select the Color ramp.
  10. If there are Breaklines select the Source file and the Attribute field to load the breaklines from.

    Note: Breaklines are defined as multi-segment lines in which the slope is monotonically increasing or decreasing along each segment. Examples of breaklines include stream or river traces, cliff faces, dredged channels, topographic ridge lines or roadways. By incorporating break lines into the gridding process the output grid is forced to conform specific slope requirements in critical areas.

  11. Expand Triangulation.
    1. Select whether to check Distance specified in data units, This parameter is used to control the units of distance that the maximum triangle side length property is measured in. By default this control is disabled and the maximum distance unit is expressed as a ratio of the tile (or patch) size. If you wish to constrain the Maximum triangle side length to a fixed value that is measured in absolute data units (e.g. 100 m) then enable this control and enter in the appropriate value. If the entered value is large and exceeds the size of an individual tile of data then it may have no effect on the output grid.

      Note: If the coordinate system of the input data is Longitude/Latitude then the absolute distance units need to be specified in fractions of a degree (Arc seconds).

    2. Set the Maximum Triangle size, this parameter applies to the triangulation phase of gridding and is used to minimize or eliminate long thin triangles that may be created across large holes or gaps in the data or between widely separated points that lie around the perimeter of the dataset. By default triangles that are created with a length that is greater than half the diagonal length of a tile is discarded. The size of the tiles used during triangulation are determined automatically by the software after it analyses the spatial statistics of the input points, however you can modify the size of the tiles by applying a triangle patch multiplier.
    3. Set the Triangle patch multiplier, the triangle patch multiplier is used to modify the number and size of tiles (or patches) that the software segments the input data into before sequentially triangulating it. The tile size is automatically determined by the software following a detailed analysis of the spatial statistics of the input data. Under certain circumstances the patch size can be modified by applying a triangle patch multiplier. Increasing the default value of 1 to a higher number creates larger patches and may assist in the infilling of large holes or gaps in the dataset, however it also increases peak memory usage during the gridding phase. For very large datasets increasing the Triangle patch multiplier reduces the number (but not the storage requirements) of temporary files that are created during the gridding phase. For most datasets a patch multiplier of 1 or 2 is sufficient. Increasing the patch multiplier beyond a value of 4 would be rarely necessary.
  12. Expand Geometry and set Cell size.

    Note:Cell size is the size (or resolution) of each cell in the output grid file. The size is measured in the spatial units of the output grid coordinate system.

  13. Select whether to Define raster geometry.
  14. Expand Advanced. 
    • To Scan data extents controls the resolution at which the software initially scans the input data files to establish the preliminary spatial statistics during the first phases of gridding. The default behaviour is to scan all lines of the input data. It is possible to speed up the initial scan of the input files by adjusting the scan data extents control to one of the following settings:
      • Complete—Scans every line of each input data file.
      • Fine—Scans approximately 12% (1-in-8) of the lines from each input data file.
      • Course—Scans approximately 3% (1-in-32) of the lines from each input data file.
      • Overview—Scans approximately 0.75% (1-in-128) of the lines from each input data file.
      • Bounds—Acquires the data extents from information stored in the files if available or performs an overview scan if unavailable.

        Note: For datasets that have a relatively even spatial distribution of input points setting the scan data extents control to Overview provides the best compromise between speed and a representative statistical sample.

    • Select the Output Raster data type, the data type control is used to set the numeric storage type for the interpolated values in the output grid. It is advisable to select the appropriate data type that most efficiently represents the range of data that is stored in the output grid. For example, a signed 2-byte integer is generally suitable for storing typical elevation data at 1m vertical resolution. The data types available are:
      • Automatic
      • Unsigned byte
      • Signed byte
      • Unsigned short
      • Signed short
      • Unsigned int
      • Signed int
      • Float

      Note: The automatic option sets the output format to an appropriate data type based on an analysis of the input data range.

  15. Select whether to Clip output raster.
  16. Click Run.