Interesting Applications of Laser Scanning

Laser Scanning

                                               

Laser surveying, or 3D laser scanning is very simple in principle. A laser scanner is mounted on a tripod next to the area to be scanned. The scanner fires a laser and measures the time it takes for the laser to be reflected back, with which it can calculate the distance from the reflected point. The scanner systematically sweeps the room with these measurements until it has a complete picture of the 3-D space around it. This collection of measurements is called a point cloud, and is the data set from which we can extract valuable information and 3-D models.

Image by Defence-Imagery from Pixabay 

Types:

• Aerial (or airborne)
• Terrestrial, mobile
•  Desktop (or benchtop)
• Hand scanning

Terrestrial Application of Laser Scanning

Laser scanning is used in architecture, engineering, construction, manufacturing plants, airports, hospitals, bridges, offshore platforms, virtual reality, heritage preservation, forensics - virtually all capital projects require rigorous design review.

LiDAR

Terrestrial Laser Scanning technology is based on Light Detection and Ranging (LiDAR). LiDAR measurements, combined with the orientation and position of the scanner, produce a 3-dimensional “point cloud” dataset. The primary capability of TLS is the generation of high resolution 3D maps and images of surfaces and objects over scales of meters to kilometers with centimeter to sub-centimeter precision. This allows for high accuracy mapping as well as the determination of surface changes over time via repeat measurements.

                                                                                                                                    

·        Civil engineering, Transportation and Surveying:

Civil engineering and surveying companies use laser scanning technology for cost effective preliminary surveys to develop TIN meshes of roadway surfaces; safer and quicker measurement of bridge beam cambers; volume calculations of quantities of rock, soil and other material; and, where safety is a concern such as accurately measuring the surface of a highway active with traffic or scanning the underside of a bridge damaged by a truck.

       

Construction:

             This technology is a valuable tool for 

reduction of construction costs by eliminating 

3D design errors that could cost thousands, or

 even hundreds of thousands, of dollars in project 

delay costs; to determine whether designs are 100% 

ready for construction and eliminate design problems 

that could hinder the construction cycle's 

timely completion.

Traffic construction

                                        Laser scanners are used more and more as surveying instruments for various applications in traffic construction analysis. Especially tunnels and road conditions are relevant to offer a continuous monitoring. As traffic is increasing steadily the infrastructure has to be in proper conditions. With traffic and transported goods increasing, detailed information of the network (clearance of bridges and tunnels, rut etc.) has to be monitored.

Forensic:

     Laser scanning is able to model and analyze forensic information from real-world scenes. Detailed 3D data is easily modeled and exported to other specialized software for visual examining scenes to determine causes and sequence of events. Measuring points of interest using conventional methods has limitations - areas are missed or just not covered in sufficient detail, requiring personnel to return to the scene to get additional information. With laser scanning, everything in range is quickly captured in 3D as well as distant structures which can play a significant part in the total interpretation. Contouring and surface modeling make it easy to build surfaces and topography to improve scene visualization.

GEO-Science:

                    Terrestrial Laser Scanning is a powerful geodetic imaging tool ideal for supporting a wide spectrum of user applications in many different environments. Geoscience applications to date include detailed mapping of fault scarps, geologic outcrops, fault-surface roughness, frost polygons, lava lakes, dikes, fissures, glaciers, columnar joints and hillside drainages.

Repeat Terrestrial Laser Scanning surveys allow the imaging and measurement of surface changes through time due, for example, to surface processes, volcanic deformation, ice flow, beach morphology transitions, and post-seismic slip. The addition of digital photography yields photorealistic 3D images. It has been demonstrated that TLS derived 3D imagery is a unique and powerful tool for educational and outreach applications as well.

Advantages:

·         Speed of data capture - reduces time and cost.

·         Remote acquisition and measurement - increases efficiency and safety of surveys.

·         High point density data ensures a complete topographic survey.

·         Abundance of data captured in laser scanning reduces questionable data, provides oversampling to ensure accuracy and that all objects, structures, geometry are captured.

·         High-density, accurate data are direct measurements.

·         Imagery and 3D visualization provides added confidence that mapped objects correspond to actual existing conditions.

·         Increase speed and accuracy of plans, elevations, profiles, volumes, and area calculations

·         Capture complete, highly detailed, accurate 3D geometry - detailed topographic surveys.

Aerial Application of Laser Scanning

Aerial laser scanning at GEODIS

GEODIS has great deal of experience with the use of different technologies for aerial laser scanning.

Today  use of  MK II device from the Swedish company Topeye for very precise projects reveal growing application of this technology.

In 2001, several projects were performed using this technology, aimed especially at the documentation of the river basins of waterways and an elaboration of 3D models with flood analysis, in 2005 we realized several projects focused on the digital highway model with high accuracy (mz = 36 mm), airport model, models of smaller waterways in order to obtain a profile of the river-basins and modelling of flood situations, forest stand model for the purpose of observing the growth and development of the forest, a precise city model connected to an orthophotomap of high resolution (pixel 5 cm), surface model above gas lines, 3D survey of transference electrical system and their zones of protection, or airport and railway models.

Air-Borne Laser Scanning and LiDAR Mapping System:

                                                                                                                  

    There are many characteristics of Air Borne Laser Scanning which makes it well suited for its uses in Laser scanning. The following figure shows the way of capturing image in aerial Laser scanning. 

The left image show the result of aerial Laser scanning which generates a 3-D Model of Terrain and it facilitates in many ways

  

Applications for forest biomass management:

                                                                                     

Another aerial application of laser scanning is in forest biomass management. The following fig shows the graph of DBH (Diameter at Brest Height) vs. Height of tree. This shows the changes in graph in different stands.

Acknowledgements: 

• Hafiz Zaka Ullah 
• Asif Sultan- 
• Ahsan Mukhtar 
• Haris Fawad 
• Jahanzaib Nisar 
• M Aqib Shehzad 

Reference:

http://sluzby.geodis.cz/services/terrestrial-laserscanning

http://www.spatialresources.com/id77.html

http://www.spatialresources.com/id76.html