Lidar

This issue of GIM is largely devoted to emergent Lidar technology. We have a feature on 3D-visualisation of Lidar data co-authored by new contributing editor Dr Bharat Lohani of IIT Kanpur India, and no fewer than two product surveys, one on Airborne Lidar Systems, the other on Lidar software. Two regular features, Technology in Focus and Company’s View, this month address processing the product of Lidar survey, point-clouds. Lidar is without doubt a most successful data-acquisition technique. As an acronym of Light Detection and Ranging - some prefer to read Lidar as Laser Imaging Detection And Ranging - the term... (read more)
2007-01-19 12:00:00 Dr Mathias Lemmens, editor-in-chief, GIM International
2017-01-05 08:56:47

LiDAR Compressor

LizardTech has released the LizardTech LiDAR Compressor. This product enables users to turn giant point cloud data into efficient MrSID files that retain 100% of the raw data at just 25% of the file size.     Unlike raw LAS or ASCII data, LiDAR files compressed to MrSID are easily managed resources from which derivatives can be extracted over and over again. One of the key features of LiDAR Compressor is its ability to reduce LiDAR file sizes by 75% while retaining all of the points and all of the point precision and accuracy of the original file. If users... (read more)
2009-07-14 09:49:29

Lidar and Sound Modelling

Improving Existing Propagation Models
Simulation of sound propagation is key for today’s urbanised society, in which sound is omnipresent and often negatively affects people’s lives. Existing methods of sound-propagation modelling fail to capture the complexity of terrain. Airborne Lidar in conjunction with aerial photos is able to fill this gap. The authors propose a programme of research to find out how high-resolution terrain data might improve the efficiency of sound models. Sound propagation is affected by obstructing objects such as buildings and trees, and influenced by the relative location of sound source and receiver, type of intermediate ground and meteorological conditions. Computation of sound... (read more)
2007-08-11 12:00:00 Susham Biswas and Bharat Lohani, Indian Institute if Technology, Kanpur, India

Airborne Lidar Bathymetry

Mapping Shallow Rivers Under Low-flow Conditions
Although operational for more than twenty years, Airborne Lidar Bathymetry (ALB) has rarely been used in riverine areas. The US Bureau of Reclamation adopted it to study how flow change in the Yakima Rivera affected fish habitat. The authors show that ALB offers accuracy and precision at least as good, if not better than that achieved in typical survey by boat with sonar and GPS. The United States Bureau of Reclamation needed to create an accurate hydraulic model of the Yakima River in Washington State to study how changes in river flow would effect downstream fish habitat. For many years... (read more)
2006-10-23 12:00:00 David Millar, John Gerhard and Robert Hilldale, USA

The Evolution of Lidar

Single Photon Lidar Brings Higher Pulse Rates for Airborne Lidar
Current airborne Lidar systems, such as the Leica ALS series, capture one million points per second. Increasing the pulse repetition rate is the best way to achieve dense point clouds at lower costs, as the flying speed can be increased. However, the pulse frequency is constrained by parameters such as energy consumption and eye safety. Single photon Lidar enables a much higher pulse rate to be achieved, since much less energy is needed per pulse. (By Ron Roth, Leica Geosystems, and Marcos Sirota, Sigma Space Corp.) Lidar systems are typically constructed from a number of components: a range-finding system, scanning... (read more)
2017-02-14 04:25:33

Airborne Lidar in Rainforest

Towards a UAV-based System for Measuring Canopy Height
At the experimental forest site Paracou in French Guiana, a range of data is being collected to enable the short-term dynamics within the tropical rainforest canopy to be better understood and quantified. Airborne laser scanning (ALS) was used to obtain high spatial resolution data of the 3D canopy structure. The data has been utilised to build a canopy height model and provides valuable information about the foliage density. The sensing system can also be mounted on an unmanned aerial vehicle (UAV). The French Guianian project demonstrates proof of concept for the further application of this technique. Within the CANOPOR research... (read more)
2014-09-01 11:42:29

Lidar Treatment Software Releases

Tiltan is to present the automatic Lidar processing product TLID - and the 3D Modelling Sensor and System AGM during Intergeo 2010.   TLiD is an automatic solution for point cloud data processing Lidar data and other, low noise, point clouds are handled. The package automatically transforms geo-referenced point clouds into GIS layers and 3D Photo-realistic dynamic presentation. The company will be represented at the Diamond booth (1F-142).   (read more)
2010-09-20 04:42:35

DragonEye Lidar System

DragonEye is AHAB\'s new Airborne Topographic LIDAR system. By offering a pulse repetition frequency of above 300 kHz, real time digital signal processing of waveform, multiple pulses in the air, and unlimited number of range captures per pulse, DragonEye represents the next generation Airborne LIDAR systems.   In addition the small size and low power consumption assures easy integration in various platforms. The system mainly consists of two collecting chains; one laser range finder for land (topographic) and a camera collecting images. The laser range finders emits pulses and measure the time distance from output pulse to return pulse in... (read more)
2008-09-30 12:30:42

Lidar-driven Innovation

The first laser was built in 1960 by Maiman, two years after Miller and LaFlamme introduced the digital terrain model (DTM) in the context of civil engineering purposes in 1958. Probably, none of them thought that by around 1995 this would solve a geomatics problem that had existed since the arrival of aerial photogrammetry: capturing terrain elevation in wooded areas. While that also required precise navigation based on GNSS and inertial systems, it was the multi-target capability of pulsed Lidar the showed unprecedented detail below the canopy. This technique has also revolutionised other fields in industry, administration and science, such... (read more)
2016-07-11 09:26:40
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