retrieve_pulses: 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)
Value
An object of class 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 the LAS object
retrieve_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 attribute scanlineID is added in the LAS object
retrieve_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 the LAS object.
LASfile <- system.file("extdata", "Megaplot.laz", package="lidR")
las <- readLAS(LASfile)
las <- retrieve_pulses(las)
las
las <- retrieve_flightlines(las)
#plot(las, color = "flightlineID")