The market for lidar applications and
lidar drones is going to increase substantially over the next decade.
Especially the use of UAVs in lidar applications. In 2015, the figure
will approach USD 300 million. However the lidar market is expected to
rise to more than $1 billion by 2020. This is an increase of 20% year on
year to 2020.
Many still view airborne lidar
applications through the use of fixed wing pilot aircraft. The high
cost or renting lidar equipped aircraft, pilots, lidar trained engineers
has kept the use of this extremely useful technology pretty much to the
minimum. Only big money and big budgets could afford to use airborne
lidar systems regularly.
With the huge leaps in drone innovation
and technology, we can see a big move away from the high cost fixed wing
aircraft to the the lower cost and more efficient UAV lidar model.
Drone manufacturers are developing
models which are adaptable for a range of cameras and sensors including
lidar. Manufacturers such as DJI with its Matrice 100 and 3D Robotics
with it’s X8-M are very adaptable for lidar sensing equipment.
The manufacturers of lidar sensors also
see the potential of the UAV market. These manufacturers are pushing
towards creating lighter and smaller lidar sensors specifically for the
UAV market. This is already happening in photogrammetry and in aerial surveying.
UAV Lidar Applications Have Huge Potential
There are many projects from commercial
to governmental, environmental and conservation which have tight budgets
and could not afford the high cost of hiring lidar equipped aircraft
services. These sectors are starting to take advantage of the low cost
of UAV lidar systems.
What is Lidar Answered
Lidar, (Light Detection and Ranging) by
definition is a remote sensing method which uses pulsed laser light to
measure ranges (variable or changing distances) to the Earth. The lidar
instrument fires rapid pulses of laser light at a surface, some at up
to 150,000 pulses per second.
Light moves at a constant and known
speed so the lidar sensors can easily calculate the distance between
itself and the target with high accuracy. By repeating this in quick
succession the insturment builds up a complex ‘map’ of the surface it is
measuring. With airborne LiDAR other data must be collected to ensure
accuracy.
Lidar
uses ultraviolet, visible, or near infrared light to image objects. As
the sensor is moving, the height, location and orientation of the
instrument must be included to determine the position of the laser pulse
at the time of sending and the time of return. This extra information
is crucial to the data’s integrity.
The National Ocean Service
best describes lidar as follows: When laser ranges are combined with
position and orientation data generated from integrated GPS and Inertial
Measurement Unit systems (IMU), scan angles and calibration data, the
result is a dense, detail-rich group of elevation points, called a
“point cloud.”
Each point in the point cloud has
three-dimensional spatial coordinates (latitude, longitude, and height)
which correspond to a particular point on the Earth’s surface from which
a laser pulse was reflected. The point clouds are used to generate
other geospatial products, such as digital elevation models, canopy
models, building models, and contours.
Lidar can also target a wide range of
materials, including non-metallic objects, rocks, rain, chemical
compounds, aerosols, clouds and even single molecules.
Lidar Applications Using UAVs
Lidar is used in so many sectors at
present on a limited basis. Lidar is going to move into more areas and
being used more frequently within these sectors. The only limiting
factor to the use of UAV lidar technology has to be our own
imaginations.
One of the best uses for lidar
is in the analysing of data within the environmental conservation
field. Many conservation projects are local community, city or county
based without having a big budget. With lidar mounted on UAVs, using
drones in locally based community projects will increase dramatically.
Having an aerial view as well as building topographic maps will benefit
all conservation projects immensely.
Positive Uses For Lidar Drones
Protecting our natural habitats for both
wildlife and ourselves is important. All life is important and to be
surrounded by unspoiled natural beauty whether it is lakes, parks,
forest or coastal region is something to cherish. Without doubt, lidar
UAVs will have a huge impact in this sector.
Here’s a list of UAV lidar applications.
This Sector is pretty big and increasing through the use of drones
adapted to carry lidar sensors.
- Agriculture: Used to reveal slopes and sun exposure on farm land.
- Agriculture: Blend topography maps with crop yield data to indicate health of soil.
- Archaeology: Locating and mapping features beneath forest canopy.
- Archaeology: Site surveying and aiding in the planning of digs.
- Meteorology: Lidar systems profile clouds, measure wind speed and quantify atmospheric components.
- Environmental Conservation: Lidar has many applications in accessing and analyzing rivers, lakes, coastal regions, climate, forest fire hazards, land based threats to Coral Reefs, measuring biomass areas and protecting forestry.
- Mining: Lidar is used to calculate ore volumes by periodic UAV flyovers ancomparing surface data to previous scan.
- Surveying: UAV with lidar sensors are used create many types of DEM (Digital Elevation Model).
- Contour Mapping: Creating topographic maps, which shows valleys, hills and the steepness of slopes.
- Solar Energy: Lidar to assist City and County planners on how best to optimize solar photovoltaic systems.
- Obstacle Avoidance: All types of autonomous vehicles including UAVs use lidar for obstacle detection and avoidance.
Here is a nice video from Dr Nicholas
Coops who provides an introduction to lidar for natural resource
management. Nicholas describes lidar very well along with the it’s
tremendous benefits.
UAV Lidar Systems
Most UAV lidar systems integrate the following components:Lidar Laser Sensors:
Generally UAV lidar systems
use 1064nm diode pumped YAG lasers. Sensors can be distinguished based
on the scanning method, i.e. how the laser beam is directed through the
surface. The four most widely used sensor types are shown.
Lidar Technology
Scanners And Optics Sensors:
The speed at which images can be
developed is affected by the speed at which it can be scanned into the
system. A variety of scanning methods are available for different
purposes such as azimuth and elevation, dual oscillating plane mirrors,
dual axis scanner and polygonal mirrors. They type of optic determines
the resolution and range that can be detected by a system.
Photodetector and Receiver Electronics
The photodetector
is the device that reads and records the signal being returned to the
system. There are two main types of photodetector technologies, solid
state detectors, such as silicon avalanche photodiodes and
photomultipliers.
UAVs, Waypoint Navigation and GPS
When a LiDAR sensor
is mounted on a mobile platform such as satellites, airplanes or
automobiles, it is necessary to determine the absolute position and the
orientation of the sensor to retain useable data. Global Positioning
Systems provide accurate geographical information regarding the position
of the sensor and an Inertia Measurement Unit (IMU)
records the precise orientation of the sensor at that location. These
two devices provide the method for translating sensor data into static
points for use in a variety of systems.
Autonomous flight
using waypoint navigation is essential to working with lidar sensors and
instruments. With autonomous waypoints, you just need to program in
the flight path or area to cover. The UAV will keep to this flight path
better than any manual piloting. The flight systems on the top drones
today, re-align themselves hundreds of times every second to keep them
still in in blustery conditions.
UAV Lidar Systems
Leica Geosystems
Leica manufacture
affordable city mapping Lidar systems with their industry leading 1.0
MHz pulse rate, which is easily upgradable to a full-capability
configuration. Leica systems produce high density point clouds for
corridor, urban, flood plain and general purpose airborne mapping in a
fraction of the time it took previously. Leica have 9 airborne lidar systems.
Phoenix Aerial Systems
Phoenix are a
leading manufacturer of UAVs with integrated aerial lidar products.
They have two terrific lidar UAVs called the Scout and Ranger.
The Scout UAV
uses the Velodyne VLP-16 puck Lidar sensor (see below), which features
16 lasers aligned over a 30º Vertical Field of View, 100+ meter range
and captures up to 300,000 measurements per second. The Ranger is by far
the most accurate and longest range lidar mapping system which Phonenix
offer. Their Lidar UAVs are ideal for mapping power lines, pipelines,
railway tracks and anything else where accuracy is essential.
Phoenix have 3 Lidar Mapping Systems.
- Ranger LiDar Series
- Aerial LiDar Al3-16
- Aerial LiDar Al3-32
Velodyne Lidar
Perhaps the most advanced Lidar sensors on the market. Velodyne’s new PUCK™ VLP-16 lidar sensor is the smallest, newest, and most advanced product in Velodyne’s 3D lidar product range. Vastly more cost-effective than similarly priced sensors, and developed with mass production in mind, it retains the key features of Velodyne’s breakthroughs in lidar: Real-time, 360°, 3D distance and calibrated reflectivity measurements.Vulcan UAV
Vulcan can build
standard, custom and bespoke multirotor UAV systems for many
applications and sectors including lidar. Vulcan UAV are the preferred
supplier of UAVs for the new LidarPod from RouteScene.
3DR X8-M
The X8-M from 3DR is totally adaptable and can be customized for various cameras and sensors. The X8-M has all the technology you need and is perfect for lidar applications and many other uses.
DJI Drones
They have 2 drones which can be customized for a range of cameras and sensors. The Matrice 100 is stable, modular, and fully programmable. The Matrice 100 is a powerful platform which is adaptable for many uses.
Another terrific is the DJI Spreading Wings S1000+ multirotor which is extremely adaptable and can carry various cameras, gimbals and sensors.
In the below video
we see the Spreading Wings S1000 mounted with the AL3-16 lidar mapping
system. The AL3-16 can be fitted on any UAV which can carry a payload
of 2.5kg. The Spreading Wings S1000 is perfect for many lidar
applications.
Lidar Training
Working outdoors with lidar sensors attached to a UAV and then developing the data to create maps and models is pretty exciting. It certainly is an adventure. To learn anything new takes some time but it is well worth it. Working with lidar is a great career move and as business, lidar services are in high demand.Here are some resources if you are new to the world of lidar. These will get you up to speed pretty quickly and then you can follow and more advanced path.
Quick and simple Introduction To Lidar training course. Another terrific read is the lidar 101 pdf.
The ESRI have 3 online lidar courses. The 1st course is
a free seminar which provides an overview of lidar capabilities using
the geographic information system called ArcGIS. This system is
used for: creating and using maps; compiling geographic data; analyzing
mapped information; sharing and discovering geographic information;
using maps and geographic information in a range of applications; and
managing geographic information in a database.
The other two courses from the ESRI include hands-on exercises and are geared toward data managers and analysts.
- Getting started with lidar in ArcGIS
- Managing lidar data in ArcGIS
- Using lidar data in ArcGIS
To finish off this post, here’s a nice video showing you exactly how lidar and remote sensing works.
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