3D Point Cloud Data Processing - Open Source Geospatial Tools: Applications in Earth Observation - page 274

-dx 1 -dy 1
Output grid cell size is 1 by 1 meter (values in output grid cells will represent
density per square meter).
-ot UInt16
Set the data type to UInt16, which can represent the maximum number of pulses
per grid cell.
-o forest_pulse_intensity.tif
Name of the output raster dataset.
It is shown that reflective targets on the ground such as soil in the lower part of the
image have a higher intensity than dense vegetation in the center of the image. Higher
intensities can be expected from reflective targets such as bare soil, whereas dark
vegetation result in lower intensities. In Fig. 15.5 b, an example is shown for a forested
area. This information can be used to detect and classify targets on the ground. If
intensity is included in a LAS file, data are normalized to a 16 bit integer. The scaling
factor is 65,536/(intensity dynamic range of the sensor). For example, if the dynamic
range of the sensor is 10 bits, the scale factor would be 64 (65,536/1,024). This
normalization facilitates the comparison of data from different sensors. However,
calibration issues hamper the quantification of intensity information in an absolute
sense and is under continuing research.