(UTIG Twin Otter and BT-67)
University of Texas Institute for Geophysics (UTIG) researchers use a multibeam, scanning photon counting laser altimeter to measure ice surface elevation. This instrument scans the surface on either side of the aircraft’s flight path with one hundred laser beamlets that allow a three-dimensional reconstruction of the ice. This laser altimeter can make over two million measurements per second and surveys a swath 400 meters (1,300 feet) wide. UTIG aircraft also carry a fixed laser altimeter, a predecessor to the scanning LiDAR, to provide comparison data.