Smart Industry No.1 2022

Light detection and ranging
(Lidar) is a remote sensing
method that uses pulsed laser
light to measure ranges
(variable distances). Similar to its
close cousins, radar using radio
waves and sonar emitting sound
waves under water, Lidar uses laser
light to accurately measure ranges
(distances) – something that is critical
for many sectors and industrial
processes.
Theoretically, measurement can be
performed using other technologies,
but Lidar has multiple advantages
over them. For example, it has
a higher resolution than radar and
a wider range than camera sensors
and can even perform in the dark.
Furthermore, Lidar produces 3D
data and can detect and differentiate
objects. As a result, it can be used
to track objects, detect physical protrusions
and survey landscapes.
Measuring carbon dioxide, sulfur
dioxide and methane in the air or
water can also be achieved with
Lidar, making it ideal for things like
geographical surveys, autonomous
driving, industrial applications and
logistics.
source ©: NOAA
The Face of the Earth
Geographical surveys are not just
for mapping mineral and water
resources, they have been used to
map zones prone to earthquakes,
tsunamis, landslides, flooding and
volcanic activity to deal with potential
disasters. In addition, coastlines
need to be surveyed for effective
management and planning for
navigational, environmental and
homeland security purposes.
As global warming raises sea levels
and causes extreme weather events
like enormous floods and droughts,
high-resolution geographical surveys
will be crucial for monitoring
the effects of global warming, such
as coastline erosion. This information
can help governments to devise
coping strategies, such as safe
and responsible land use and emergency
preparedness, to protect civilian
lives and marine wildlife.
The National Oceanic and Atmospheric
Administration (NOAA), an
agency primarily responsible for
mapping US shorelines, sought to
increase the efficiency and reduce
the subjectivity of older technologies,
such as tide coordinated aerial
photography. Data collection in intertidal
zones was also poor because
these areas are too shallow for
survey vessels to approach safely.
NOAA now uses airplanes and helicopters
equipped with two types of
Lidar: topographic and bathymetric.
Topographic Lidar typically uses a
near-infrared laser to map the land,
while bathymetric Lidar uses waterpenetrating
green light to measure
seafloor and riverbed elevations.
Lidar is helping
us understand
sea-level rises
and coastal
flooding/inundation
impacts,
and marine life
habitat mapping.
Stephen White
NOAA
National Ocean Service
Monitoring
the Warming
A view looking northeast
from Virginia Key
shows the topobathymetric
surface of the
intertidal zone near
Fisher Island. This
image was created
from the LiDAR bare
earth model colored
by elevation.
The two images can be combined to
produce a single ‘topobathymetric’
image of the coastal area.
Driving Force
How do we make sure autonomous
cars and trucks pay proper attention
and avoid disasters in near
darkness, pouring rain, heavy snow
or on a winding road?
Lidar’s high speed and accuracy enable
distant object detection on a
moving vehicle, even in low light.
This makes it a powerful technology
for advanced driver-assistance
systems (ADAS) in drones and vehicles.
It performs less well in heavy
rain and snow or in fog but work is
in progress to find ways to improve
its reliability in all but the worst conditions.
Earlier Lidar technologies were
typically used in applications with
a high tolerance for failure. In contrast,
the bar is much higher for
safety, accuracy, and reliability
when using it in autonomous vehicles.
Products need to be designed
from scratch to meet the 3D sensing
requirements of automotive active
safety systems, ADAS implementations
and autonomous vehicles. In
addition, solutions must be small
and unobtrusive which is a challenge
for Lidar.
83
source ©: NOAA