LVIS Images

The LVIS returns can be plotten on a map, with any of the parameters colored.  These are from the survey of Gabon.

The maps can display two things:

The scan pattern from LVIS, which is parallel to the flight path.

The aircraft flew NW to SE.
Because LVIS records the top and base of the waveform, software can compute the horizontal distance traversed by the wave.

This connects the two points, EDIT" buttonField geometry, Distance between two points in record

The distance is typically < 2 m
Unlike typical scanning lidars which scan on either side of nadir, LVIS scans to the front of the aircraft.  Points directly along the flight path are about 3 degrees, which those on the edges of the swath are about 8 degrees.  This angle is the number of degrees, measured from vertical (off-nadir).  This is never very large, and accounts for the small ground footprint of the returns in each pulse.
ZG: --This would be a DTM if converted to a grid.  The low points are streams on the SE edge of the map (nearly the same height in ZT, and with a CHM near 0).
ZT: --this would be a DSM if converted to a grid
RH100, or CHM
Azimuth of the laser pulse.  The aircraft flight path is in the center, to the SE, about 130 degrees, and it scans to the left and right.  You should think about this geometry with the incident angle.

Range of the pulse.  This portion of the record shows:

  • Steady climb of the aircraft as it flew SE
  • With each pulse, the smallest range is at the center, and the largest on either side as the laser swung left and right.
SHOT or pulse NUMBER.  The increase in numbers shows the flight direction, NW to SE.

 


Last revision 12/12/2017