AERIAL LIDAR SURVEY
Is there a faster way to get detailed terrain and topology as well as existing structures in a wide stretch of land other than traditional surveys?
The client wanted to design a structure that would pass through a highly urbanized area. They needed a detailed as-built and topographic survey so that they could generate the most economic and feasible design possible for their structure. GGC Survey’s Professional Land Surveyors perform an aerial LiDAR survey to obtain accurate horizontal and vertical positioning of all existing features on site. About 150 acres of data was obtained and transformed into a LiDAR Point Cloud. What would normally take about 3 months of traditional survey work in the field was done in about two (2) hours of LiDAR 3D Mapping in the sky.
An aerial lidar survey is a type of remote sensing technology that uses lasers and sensors to create highly accurate 3D models of the earth's surface. The term "lidar" stands for "Light Detection and Ranging," and the technology works by emitting pulses of laser light from an aircraft or drone and measuring the time it takes for the light to reflect back to the sensor.
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During an aerial lidar survey, the aircraft or drone flies over the area to be surveyed and emits thousands of laser pulses per second. The laser beams reflect back to the sensor and create a detailed 3D point cloud of the earth's surface. This point cloud can then be used to create highly accurate elevation models, terrain maps, and other types of geospatial data.
How is it useful?
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Digital Elevation Model (DEM): Measures the elevation of points and generates a digital terrain model of the tract of land.
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Utility Mapping: Can be used to show utilities such as power lines, poles and above ground pipes.
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As-Built Maps: Elevations of structures could also be derived from the LiDAR Point Cloud.
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Speed: Ideal for large tracts of land that needs to be surveyed for a short period of time.
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Agriculture: LiDAR helps the farmer to find the area that uses costly fertilizer. LiDAR can be used to create elevation maps of the farmland that can be converted to create slope and sunlight exposure area maps.
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Forest Planning and Management: It is used to measure vertical structure of forest canopy and also used to measure and understand canopy bulk density and canopy base height and peak height to estimate its root expansion.
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Flood Model: River is very sensitive and a few meters of change in information can bring disastrous or loss of properties. So accurate extracted LiDAR information can be used for the 3D simulation for better planning of the structures or buildings on the river bank.
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Transport Planning: As LiDAR is highly accurate technology it helps to understand width, elevation and length of the existing road.
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Urban planning: Lidar can be used to create detailed 3D models of buildings and urban areas, which can be useful for urban planning and development.
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Railway Infrastructure: Traditionally railway track measurement was done by a regular survey system. Now LiDAR can quickly perform the measurements of the railway track and the topographical and surrounding area of the railway path.
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Airport Infrastructure: Used to capture features in the airport like runway, terminal building that allow airport authority to manage and operate the airport system smoothly.
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Mining: LiDAR is also used in the mining business in various tasks. It is used to measure the ore volume by taking a series of 3D laser measurements of ore extraction spaces. These measurements would then generate a 3D surface in which data such as cavern volume could be extracted. It could also be used to get mine cross-sections for liquid flow analysis.
