Ever imagined that you can
calculate how far everything is away from you? Yes, LiDAR (Light Detection and
Ranging) does this for you. Excited to know what is LiDAR? What are its types and what
magic it can perform in this era of modern technology? Let’s have a quick look!
What is Lidar (Light
Detection and Ranging)?
Basically, LiDAR is a distance
technology. It is the latest disruptive technology having its use in various
fields and now in the construction industry as well. From an aircraft or a
helicopter, the lidar system actively sends light energy to the ground. The
signal hits the ground and returns to the sensor.
What are the types of
Lidar?
There are basically two types
of Lidar: Airborne and
Terrestrial Lidar systems.
Let’s take a close look at each
type one-by-one.
1 1. Airborne Lidar
The
Light Detection and Ranging is an exciting technology to know. In the Airborne
Lidar, the system installs on the wing of an aircraft or helicopter. The
infrared lights are emitted towards the ground, and it returns to the moving
airborne lidar sensor. There are two main types of airborne sensors:
Topographic and Bathymetric Lidar
2 2. Topographic Lidar
The
Topographic Lidar marks its presence to obtain surface models that are useful
in many applications such as forestry, urban planning, landscape ecology,
coastal engineering as well as survey assessment, etc.
3 3. Bathymetric Lidar
Bathymetric
Lidar is a type of airborne lidar that is water penetrating. Many of the
bathymetric lidar systems use in collecting elevation and water depth which
provides an airborne lidar survey of the land-water interface.
Traditionally,
in Bathymetric Lidar systems, the infrared light reflects back to the aircraft
from the land and water surface. While the additional green laser travels
through the water column and therefore measures the exact distance. To
establish water depths and shoreline elevations it uses the analysis of two
different pulses.
The
Bathymetric information has its significance near coastlines, in harbors and
near shores and boundaries of rivers. The Bathymetric information is also
helpful in locating objects on the ocean floor.
Now
let’s move on to the next type of Lidar: Terrestrial Lidar
4 4.Terrestrial Lidar
In this
Lidar system, there are two main types: Mobile and Static
In the
case of mobile, as the name suggests, the lidar system is fixed on a moving
vehicle. Whereas, in the case of static, the lidar system is fixed on a tripod
or on a stationary device. Both the lidar sensors comprise eye-safe lasers.
The
Terrestrial Lidar compiles very dense and highly exact points which allow
accurate identification of objects. These compact point clouds are used to
manage facilities, conduct highway and railway surveys and even use in creating
3D city models for exterior and interior spaces.
Following
is the brief look at Mobile and Static Lidar
5 5.Mobile Lidar
It is
the collection of lidar point clouds from a moving base. Mobile Lidar systems
include any number of lidar sensors fixed on a moving vehicle. These types of
systems mounts on vehicles, trains and even on ships. The Mobile systems
consist of a Lidar sensor, cameras, GPS (Global Positioning System), and an INS
(Inertial Navigation System) same as like of Airborne Lidar systems.
The
Mobile Lidar data is not only useful in analyzing the road infrastructure but
also helps in locating the trespassing overhead wires, light poles and various
road signs near roadways or rail lines.
6 6. Static Lidar
It is
the gathering of lidar point clouds from a static location. Typically, in
static lidar, a portable laser-based imaging and ranging sensor are placed on a
tripod. These systems collect the lidar point clouds from inside as well as the
exterior of the building. The typical application of static lidar systems is
engineering, mining, surveying, and archeology.
Lidar Data is
precious GIS resource
The Light Detection and
ranging, i.e., LiDAR is accurate and covers the large areas on the ground. You
can also visualize bare ground elevation, canopy heights, light intensity and
much more. Anyone who is looking for understanding landscape topology should,
therefore, use LiDAR.
With its tremendous working
capabilities, LiDAR is a behemoth of a data set to work with. It uses LAS file
format to store the LiDAR files as a point cloud data and hence, streamlines
smooth exchange between vendors and customers with no loss of information.
LiDAR Applications
The Light Detection and Ranging
make use of lasers to measure the elevation of features like forests, buildings
as well as of the plain earth.
It is somewhat similar to sonar
(Sound waves) or radar (Radio Waves) as it also sends a pulse and measures the
exact time it takes to return. LiDAR is difficult from sonar and radar as it
uses light to measure the accurate time as well as distance.
The LiDAR applications are
impressive and are undoubtedly growing in GIS systems.
Following are some
LiDAR Applications:
Forestry, Archaeology, land use
mapping, flood modeling, transportation planning, architecture, oil and gas
exploration, public safety, automated vehicles, military, and conservation also
make use of Lidar.
We try our best to explain the
Light Detection and Ranging. Hope this guide is helpful for you.
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