LiDAR Services

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LiDAR Services are the various functions that can be performed by means of the LiDAR technique. LiDAR is one of the premier technologies that is used widely in Optical remote Sensing. LiDAR is Light Detection And Ranging. LiDAR (Light Detection And Ranging) is the Remote Sensing technology that can determine the range and other information about a particular distant object. This is done by means of measuring the properties of scattered lights.

The LiDAR Services are the products of LiDAR survey. The quality of LiDAR Services depend upon the quality or accuracy of data collected during the LiDAR Survey.

A LiDAR (Light Detection And Ranging) sensor emits 500 to 50,000 laser pulses per second in a scanning array. The sensor scan side to side as the aircraft flies over the concerned survey area. This is done by the help of a pulsed laser beam. As this scanning goes on, simultaneously 20,000 to 1,00,000 points are registered or measured per second. The informations about the points or objects are calculated fro the time interval of the LiDAR (Light Detection And Ranging) pulses. The time delay of these transmitted pulses and detected reflected signals are taken as a distance of an object or surface. The spacing of these points depend upon the flying height and scan angle.

The LiDAR (Light Detection And Ranging) System comprises of another three important technologies which work simultaneously with the LiDAR sensor. They are :

Laser Scanner Inertial measurement Unit (IMU) Global Positioning System (GPS)

Types of LiDAR Service:

The LiDAR System provides the following LiDAR services:

 

One of the services rendered by the LiDAR System is the Topographic Survey. The elevation data are collected by means of laser lights. In this regard it must be noted that the LiDAR technology can collect the data with an accuracy of 15 cm. The topographic survey is exclusively carried out in assistance with the airborne Global Positioning System (GPS). GPS determines the x coordinate, y coordinate and z coordinate of the concerned point. This coordinates are recorded and called as raw LiDAR point file. The elevation data that are recorded is called First Return DEMs. Thus, one of the important LiDAR Services is the Terrains Analysis. LiDAR Services in the field of Hydrology is also worth mentioning. A LiDAR System scans the coastal water, bottom relief of the ocean etc. The time interval between two successive reflected pulses at different wavelengths are taken as a water depth. One pulses travel through the air water to the water bottom while another one is reflected from the water surface. Thus, the depth of the water along with the idea of the ocean bottom topography can be determined by a standard LiDAR System. The LiDAR Services also plays an important role in Bathymetric Survey. By this technology one can determine the depth of the moderately clear, near shore coastal water and other water bodies. One of the most important aspect of the LiDAR Services is that it can generate the 3-D model of the earth surface. The LiDAR data integrated with the GIS can produce the 3-D models like DEM (Digital Model Elevation), TIN (Triangular Irregular Network) and DTM (Digital Terrain Model). This 3-D models helps in terrain analysis, spatial analysis and geomorphological studies.

Fields of LiDAR Services:

The fields of LiDAR Services are:

• Geological, Glacial, Geographical and Geomorphological studies.
• Meteorology
• Forestry
• Oceanography
• Defense
• Urban Planning

The usefulness of LiDAR Services are endless in the present world.