Geoscience Reference
In-Depth Information
15.3.5 SPDLib
SPDLib is an open source library for processing laser scanning data.
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It introduces
its own data format, referred to as sorted pulse data (SPD). The library can handle
both discrete return and full waveform data. A unique feature of SPDLib is that data
are explicitly processed as pulses rather than points. SPDLib also includes a Python
binding to allow easy access to the underlying data making use of the SPD spatial
index. It comes with a set of command line utilities, such as
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:
spdtranslate
Translates data to and from various LiDAR files formats (similar to
gdal
_translate
), but is most commonly used to translate data to the SPD
format required by the other commands. Options on this command allow data
to be re-projected and indexed into the SPD grid.
spdpmfgrd
Provides an implementation of the progressive morphology filter (Zhang et al.,
2003) for the classification of ground returns.
spdmccgrd
Provides an implementation of the multiscale curvature algorithm (Evans and
Hudak 2007) for the classification of ground returns.
spddefheight
A command to populate the height field with the SPD file, the SPD format pro-
vides both a z (height above the datum) and a height field (height above the ground
surface). This is used to calculate vegetation metrics, for example.
spdinterp
Acommand to interpolate raster surfaces for the point cloud includingDTM, DSM
and CHM (see Sect. 15.4).
spdmetrics
Akin to a 'LiDAR Calculator' this command uses an XML file to specify a set of
metrics which are to be calculated, using a set of LiDAR primitives (e.g. num-
ber of returns above height X or height percentile) and operators (add, minus,
multiply, divide etc.).
An example of using SPDLib to convert a LAS file to the SPD format, classify
ground returns, define the height field, interpolate DTM and CHM surfaces and some
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Check
http://www.spdlib.org/doku.php?id=spdlib:users:users#command_line_tools
for a com-
plete list of utilities.
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