Input observation vector map name (v.lidar.growing output)
output=name
Output classified vector map name
out_terrain=name
Output terrain only vector map name
database=string
Database name
driver=string
Driver name
Options: sqlite,ogr,pg,odbc,dbf,mysql
sce=float
Interpolation spline step value in east direction
Default: 25
scn=float
Interpolation spline step value in north direction
Default: 25
lambda_c=float
Regularization weight in reclassification evaluation
Default: 1
tch=float
High threshold for object to terrain reclassification
Default: 2
tcl=float
Low threshold for terrain to object reclassification
Default: 1
DESCRIPTION
v.lidar.correction is the last of three step to filter LIDAR
data. It makes a comparison between the LIDAR observations and an
interpolated surface in which only terrain points have been used. Once
the new reference surface is obtained, a point reclassification is
done:
a) Points classified as TERRAIN differing more than a threshold
value are interpreted and reclassified as OBJECT.
b) Points classified as OBJECT and closed enough to the
interpolated surface are interpreted and reclassified as TERRAIN.
The input should be the output of v.lidar.growing module or
the output of this v.lidar.correction itself. That means,
this module could be applied more times (although, two are enough) for
a better filter solution. The outputs are a vector map with a final
point classification as as TERRAIN SINGLE PULSE, TERRAIN DOUBLE PULSE,
OBJECT SINGLE PULSE or OBJECT DOUBLE PULSE; and an vector map with
only the points classified as TERRAIN SINGLE PULSE or TERRAIN DOUBLE
PULSE.
NOTES
The final result of the whole procedure (v.lidar.edgedetection,
v.lidar.growing, v.lidar.correction) will be a point classification in
four categories:
TERRAIN SINGLE PULSE
TERRAIN DOUBLE PULSE
OBJECT SINGLE PULSE
OBJECT DOUBLE PULSE
Original version of program in GRASS 5.4:
Maria Antonia Brovelli, Massimiliano Cannata, Ulisse Longoni and Mirko Reguzzoni
Update for GRASS 6.X:
Roberto Antolin and Gonzalo Moreno
REFERENCES
Brovelli M. A., Cannata M., and Longoni U.M., 2004, LIDAR Data Filtering and DTM Interpolation Within GRASS, Transactions in GIS, April 2004, vol. 8, iss. 2, pp. 155-174(20), Blackwell Publishing Ltd
Brovelli M. A. and Cannata M., 2004, Digital Terrain model reconstruction in urban areas from airborne laser scanning data: the method and an example for Pavia (Northern Italy). Computers and Geosciences 30, pp.325-331
Brovelli M. A e Longoni U.M., 2003, Software per il filtraggio di dati LIDAR, Rivista dell'Agenzia del Territorio, n. 3-2003, pp. 11-22 (ISSN 1593-2192)
Brovelli M. A., Cannata M. and Longoni U.M., 2002, DTM LIDAR in area urbana, Bollettino SIFET N.2, 2002, pp. 7-26
