This procedure reads a LAS-formatted LIDAR data file and converts it to either an ENVI-format file or an EVF file.

Syntax

ENVI_DOIT, 'ENVI_CONVERT_LIDAR_DATA_DOIT' [, BACKGROUND=value] [, DATA_TYPE={1 | 2 | 3 | 4 | 5 | 6 | 9 | 12 | 13 | 14 | 15}] [, /EXTRAP], FNAME=string, /IN_MEMORY | [, INTERP={0 | 1}] [, MODEL_TYPE={0 | 1 | 2}] [, OMAP_INFO=variable], OUT_FNAME=string [, OUT_IMAGE={0 | 1 | 2}] [, /OPEN] [, R_FID=variable] [, /VECTOR]

Keywords

Note: The keywords DATA_TYPE, EXTRAP, INTERP, MODEL_TYPE, and OUT_IMAGE only apply when converting the LAS LIDAR data to ENVI Classic raster data. If you set the keyword VECTOR, these keywords are ignored.

BACKGROUND

Use this keyword to specify a floating-point value to use for the elevation and intensity data that lie outside the calculated triangles defined by the LAS point data. The default value is 0.

DATA_TYPE

Use this keyword to specify the IDL data type of the file, using the following IDL convention. The default data type is integer (DATA_TYPE=2).

  • 1: Byte (8 bits)
  • 2: Integer (16 bits)
  • 3: Long integer (32 bits)
  • 4: Floating-point (32 bits)
  • 5: Double-precision floating-point (64 bits)
  • 6: Complex (2x32 bits)
  • 9: Double-precision complex (2x64 bits)
  • 12: Unsigned integer (16 bits)
  • 13: Unsigned long integer (32 bits)
  • 14: Long 64-bit integer
  • 15: Unsigned long 64-bit integer

EXTRAP

Set this keyword to extrapolate the results past the bounds of the data.

FNAME

Set this keyword to a string representing the name and full path of the input LAS LIDAR file.

IN_MEMORY

Set this keyword to specify that output should be stored in memory. If you do not set IN_MEMORY, output will be stored on disk and you must specify OUT_NAME (see below).

INTERP

Use this keyword to specify the type of interpolation used to convert the data. Set INTERP to 0 for the linear method (default), or to 1 for the quintic method.

MODEL_TYPE

Set this keyword to one of the following values to indicate the type of model used to convert the data.

  • 0: Last return (default)
  • 1: Full feature
  • 2: First return

OMAP_INFO

Use this keyword to specify the output map information structure that the data should be written to. This structure should have the same format as that returned from ENVI_MAP_INFO_CREATE.

OUT_FNAME

Use this keyword to specify an output filename for the resulting data. If you set the keyword IN_MEMORY, this keyword is unnecessary.

OUT_IMAGE

Set this keyword to one of the following values to indicate the type of raster output produced.

  • 0: Elevation and intensity (default)
  • 1: Elevation only
  • 2: Intensity only

OPEN

Set this keyword to automatically open the resulting ENVI-format image file in the Available Bands List, or the EVF in the Available Vectors List.

R_FID

Use this keyword to specify a named variable that contains the file ID for the resulting ENVI-format image file or the vector ID for the resulting vectors. You can use this file ID to subsequently access the resulting processed data. This keyword returns a value of –1 if an error occurs trying to create an ENVI Classic raster file, or a null pointer if an error occurs trying to create an ENVI vector file.

VECTOR

Set this keyword to save the data as vectors to an EVF. By default, the data are converted to raster and saved to an ENVI-format image file.

API Version

4.2