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Airborne LIDAR Surveys - An Economic Technology for Terrain Data Acquisition
The following is a list of the main advantages of using LiDAR as a survey technology:
LiDAR can be applied in a multitude of applications requiring large scale mapping with most of them related to infrastructure development or maintenance. The following table presents the main applications areas. Coastal erosion analysisFlood risk mappingForestry applicationsGeo-reference location structuresGIS and high tech aerial surveysGolf & resort planningHydropower projects Large-scale civil engineering projectsLandslide risk mapping Defence applicationsMovie animation productionOpen pit miningPipelines constructionRoadway corridor planningTelecommunicationsTopographic surveysTransmission lines Figure 2 shows one sample type of data collected by LaserMap over the years - an isometric view of a terrain model for a downtown in Bun Dang City in Korea. These data are collected over a dense urban area and can be used, for example, for radio frequency coverage analysis for optimal telecommunication antenna location; or by security forces for disaster preparedness and mitigation.  Figure 2. Isometric view of LiDAR DTM over Bun Dang City, Korea © 2002, LaserMap Image Plus. All rights reserved Over the recent years, flood risk mapping has been a significant part of LaserMap’s work in Canada. For example, on the Canadian USA border in Manitoba, in central Canada, a large area was flooded in the Red River flood plain. The area shown below in Figure 3 is about eight kilometres wide. This area was subject to wide ranging floods after a winter of heavy snowfall followed by lots of spring rain in 1977. Using LiDAR the engineers were able to see where the flood lines were located and then try to take various measures to reduce risk in the future.  Figure 3. Color coded LiDAR heights by 1m interval over Red River plain © 2002, LaserMap Image Plus. All rights reserved LIDAR Survey in Sabah, Malaysia Closer to south-east Asia, here in Malaysia, LaserMap was involved in several LiDAR surveys for Public Work Malaysia (JKR). The following example was completed in Sabah during the first months of the year 2002. The mountains in Sabah are steep and covered in tropical vegetation. Indeed, this area in the northern part of the island of Borneo, a few degrees north of the equator, has the highest mountains in south-east Asia, reaching 4,175 meters. The two main cities of Sabah are Kota Kinabalu and Sandakan, which are joined by a 300 kilometres long road running through the mountains and forming the economic lifeline between Sabah’s two main manufacturing and trading hubs. A significant problem with the road, however, is much of the mountainous area through which it passes is covered with a layer of soil over the bedrock. In the heavy rainy season it is not unusual for landslides to occur which block the road, sometimes for several weeks or longer. When this happens the only way to ship goods between the two main centers is by air, which is expensive, or by sea, which is not only slow but also dangerous - as in this area shipping is often subject to attacks by pirates. In reality, neither of these methods is economic or practical for everyday commerce. |