Lidar scanner with unprecedented capabilities

NGI now has a new lidar scanner with unprecedented capabilities. The Lidar can create highly accurate "images" of the physical surroundings, and the new equipment can make images at distances of over 3 000 metres.

NGI is proudly the first European institution to publicly announce their acquisition of a new long range lidar scanner. Lidar technologies - commonly known as laser imaging, have the ability to create highly accurate and spatially dense datasets or "images" of the equipments physical surroundings. New developments in 2010 by the Canadian company Optech Inc. have resulted in terrestrial lidar equipment with capabilities of imaging at distances of over 3 000 metres. 

The Optech Ilris-3D LR scanner, as shown in the image above, has a laser repetition rate of 10 000 Hz with an achievable accuracy of 3 cm at 1000 m. The laser employed by the scanner has a 1064 nm wavelength, which reduces the effect of laser absorption by the atmosphere and water particles. This in turn allows the lidar instrument to be used for scanning of snow and ice (as well as rocks, trees, etc.).

The foreseeable applications of the scanner will be primarily in the field of natural hazard identification, evaluation, mapping and monitoring. The use of this scanner will play a large role in the success of one of NGI's strategic programs titled "Remote Mapping and Warning" as well as developing in house imaging and digital data interpretation and evaluation expertise. Multiple sites within Norway have been identified to use the equipment, operational planning for deployment in early summer is currently underway at NGI.

The range and ability of the scanner to image snow and ice has been evaluated at the NGI avalanche test site at Rygfonn, near Stryn in Western Norway. The images to thr right show the mountain area under investigation, and the resultant lidar image. Future applications at the Rygfonn site include avalanche path analysis, snow thickness evaluation, and differential volume (failure) calculations. These analyses will be the first ever completed with high-density, high-accuracy, 3-dimensional lidar data. The ability to do such measurements will in turn lead to better understanding of snow avalanche mechanics, and greatly aid in determining the risk associated with avalanche hazards.

The acquisition of this outstanding instrument will greatly aid NGI's Geophysics and Remote Sensing group in development of state-of-the-art workflows and analysis techniques for natural hazard mapping and monitoring. This equipment purchase illustrates the continued dedication of NGI to use the most advanced tools and technologies in order to solve the most challenging problems relating to the earth sciences and geotechnical engineering.

At the NGI avalanche test site at Rygfonn, near Stryn in Western Norway, the world first long range snow and ice scanner was deployed (Optech Ilris LR). The above video illustrates the challenges of working in such conditions and systems required to complete a single 3d lidar survey. The video shows both the blasting tower used to activate radio controlled explosives designed to generate avalanches, and the survey station in which the lidar data were collected.