Permanent Terrestrial Laserscanner
"Im hinteren Eis"

Brief summary

Location Rofental, Ötztal Alps
close to summit "Im hinteren Eis" (3270 m a.s.l.)
(46°47'42.57", 10°46'57.98")
Instrumentation Terrestrial Laserscanner (Riegl VZ-6000)
Range up to 6 km, Wavelength 1050 nm - perfect for ice and snow
Autumn 2016 timeline arrow Basic installation (Container, Scanner)
Autumn 2016 to Spring 2018 Test with manual procedure
Spring 2018 Test of automated procedure
Summer/Autumn 2018 Start automated procedure
Aim Precise measurements of surface changes for glaciological and geomorphological applications with
  • short repeat cycles (high time resolution)
  • high spatial resolution
Partner University of Innsbruck
  • Institute of Geography
  • Institute of Atmospheric and Cryospheric Sciences
Funding University of Innsbruck, Austria
Austrian Federal Ministry of Science, Research and Economy (BMWFW)

Location

Close to summit "Im hinteren Eis" (approx. 3200 m a.s.l.) above the orographic right side of Hintereisferner, Ötztal Alps, Tyrol (see Figure 1) a measurement site which includes a terrestrial laser scanner (TLS) was instrumented in autumn 2016. Additionally, a fully equipped automatic weather station (AWS) with an extended instrumentation (e.g. 6 m tower for flux-measurements at different levels) is installed very close to the TLS position. The basic set-up foresees the installation of additional components.


Karte vergrößern
Figure 1: overviewmap, todo ...

Aim

The aim of the TLS measurements is to repeatedly measure volume changes of Hintereisferner with a high temporal and spatial resolution to make substantial contributions to the exploration of the mass budget of Hintereisferner and associated processes (e.g. snow re-distribution by wind, avalanches) as well as the understanding of the dynamics of alpine type glaciers. The measurements also offer the opportunity to quantify and analyse geomorphological and glacio-morphological processes in the vicinity of the glacier. Furthermore, it is intended to pass the measurements and the respective analysis on to process modelling groups as high resolution validation data (e.g. avalanche modelling).

Instrumentation

The installed TLS is a long-range Riegl VZ-6000 (www.riegl.com) scanner with the optimal wavelength for observing snow and ice surfaces. The main features of the VZ-6000 are:

  • Range: 6000 m
  • Wavelength: 1050 nm
  • Field of View: 60° vertical, 360 ° horizontal
  • Measurements per second: 23000 to 222000
  • Beam divergence: 0.12 mrad (~ 0.12 m @ 1000 m)
  • Temperature range measurements: -10°C to +50°C
  • -"- (without Protective Housing): -20°C, if TLS is in use
  • Integrated camera: 2560x1920 pixels

The VZ-6000 laser scanner ‚Im hinteren Eis’ is placed in a standard container, which also hosts computers and other instruments, and protected by a special so-called Protective Housing (see Figure 2). The power supply to the AWS and the container is via a mains power line from the nearby ski resort Schnalstaler Gletscherbahnen.

VZ-6000 Laser scanner
Figure 2: VZ-6000 Laser scanner (left up), Protective Housing (left down, www.riegl.com) and installation inside container high above Hintereisferner (foto: R. Sailer, Department of Geography, University of Innsbruck)

Set-up status

At the moment (autumn 2017), the irregular scans are conducted with a horizontal field of view of 120° and a vertical on of 60° (see Figure 3 ). The horizontal and vertical frame resolutions are in the order of 0.01° (~0.17 m @ 1000 m). According to that the center part of the glacier tongue is captured by approx. 10 points/m2 and the accumulation area of Hintereisferner by approx. 2 points/m2.

Field of View and approx. vertical and horizontal frame resolutions
Figure 3: VZ-6000 "Im hinteren Eis" Field of View and approx. vertical and horizontal frame resolutions (foto: J. Stötter, Department of Geography, University of Innsbruck)

Expected accuracy of the TLS measurements

Analysis of the measurements already conducted yield very low (< 0.15 m) deviation of the TLS data against Airborne Laserscanning (ALS) data in stable areas, where no surface changes are to be expected from geomorphological activity. The relative deviations of the TLS scans to each other are < 0.10 m.