retrieve_pulses {lidR} | R Documentation |
Retrieve individual pulses, flightlines or scanlines
Description
Retrieve each individual pulse, individual flightline or individual scanline and assigns a number to each point. The LAS object must be properly populated according to LAS specifications otherwise users could find unexpected outputs.
Usage
retrieve_pulses(las)
retrieve_flightlines(las, dt = 30)
retrieve_scanlines(las)
Arguments
las |
A LAS object |
dt |
numeric. The threshold time-lag used to retrieve flightlines |
Details
retrieve_pulses
Retrieves each individual pulse. It uses GPS time. An attribute
pulseID
is added in theLAS
objectretrieve_scanlines
Retrieves each individual scanline. When data are sampled according to a saw-tooth pattern (oscillating mirror), a scanline is one line, or row of data. The function relies on the GPS field time to order the data. Then, the
ScanDirectionFlag
attribute is used to retrieve each scanline. An attributescanlineID
is added in theLAS
objectretrieve_flightlines
Retrieves each individual flightline. It uses GPS time. In a continuous dataset, once points are ordered by GPS time, the time between two consecutive points does not exceed a few milliseconds. If the time between two consecutive points is too long it means that the second point is from a different flightline. The default threshold is 30 seconds. An attribute
flightlineID
is added in theLAS
object.
Value
An object of class LAS
Examples
LASfile <- system.file("extdata", "Megaplot.laz", package="lidR")
las <- readLAS(LASfile)
las <- retrieve_pulses(las)
las
las <- retrieve_flightlines(las)
#plot(las, color = "flightlineID")