Is Drone Survey Accurate? This has always been the question of many
which most of them are members of the Surveyors Forum (NIS).
But before we can visit that, you need to understand what a Drone Technology, Drone Survey and Survey Drone means and also what its all about.
Mind you that a Drone Survey and Survey Drone means different things.
Lets discuss a little about it.
What is a Drone Technology?
A drone is an unmanned aircraft or ship that can navigate autonomously, without human control or beyond line of sight, according to dictionary.
The brains of a drone can be classified in the manufacture of the physical UAV, to the circuit boards, chip-set and software.
This composite material strength allows drones to fly at a very extremely high altitudes.
One of the most popular drones on the market is the DJI Phantom 3.
While slightly old now, it uses plenty of advanced technology which is present in the very latest drones.
UAV (Unmanned Aerial Vehicle) are drones that are equipped with different
state of the art technology.
These art technology are infrared cameras, GPS (Global Positioning System) and laser (consumer, commercial and military UAV).
And also referred to as a ground cockpit.
What is a Drone Survey?
Drone surveys is described as a faster, safer and more cost-efficient
way to survey at height or from the air.
It is in most cases, the popular method of surveying from the air can be
referred to as Aerial surveys.
There are two techniques for this type of survey, Photogrammetry Lasergrammetry
Photogrammetry is the science of making measurements from photographs.
It is also that branch of surveying which deals with making and production of maps such
as planimetric or topographic maps by compiling number of overlapping photographs taken in that particular area.
The input to photogrammetry is photographs, and the output is typically a
map, a drawing, a measurement, or a 3D model of some real-world object or scene.
Photogrammetry consists of two branches
- Terrestrial photogrammetry
- Aerial photogrammetry
Without taking much of your time here, you need to keep in mind that
Terrestrial photogrammetry is an important branch of the science of photogrammetry.
It also deals with photographs taken with cameras and instruments located on ground or rather the surface of the earth.
The cameras can be handheld, mounted on tripods, or suspended from towers or other specially designed mounts.
Aerial Photogrammetry can be defined as the branch of surveying that
deals with production of maps.
These maps such as planimetric or topographic maps can be gotten
by compiling number of overlapping photographs taken from the air in that area.
Platforms for aerial photography include fixed-wing aircraft, helicopters, unmanned aerial vehicles (UAV), balloons, blimps and dirigibles,
rockets, pigeons, kites, parachutes, stand-alone telescoping and vehicle-mounted poles.
Drone Surveying are also classified of two types, Interior and Exterior Drone Survey.
Interior Drone Surveying: it consists of providing a large number of measurements in order to produce a geometric representation of a building at any point.
There are many applications: industrial buildings, public buildings (sports halls, exhibition hall), historic buildings (museums, castles, churches), archaeological sites, etc.
Modeling buildings enables the production of plans, models and thermal balances which help in monitoring and documenting the evolution of a structure.
This is a key issue for better management of buildings. Good knowledge of the structure allows for implementation of evacuation or contingency plans.
Lasergrammetry is a 3D topographic survey mode.
It allows precise measurements using a scanning rangefinder device also called laser scanner or LiDAR.
This technology allows the acquisition of 3D data of large complex scenes and the direct exploitation of distances and angles.
Lasergrammetry is a true technological evolution in the topographic world
since it brings a real time saving and proposes new perspectives of result with a real precision of the renderings.
Lasergrammetry uses a laser type sensor and is based on the principle of echolocation.
The sensor measures the time between the emission of the wave and its receipt.
This calculates the distance between the source and the target.
Then knowing the angle of emission of the laser, it is possible to calculate the position of the points.
Thanks to the position of each point, we can perform precise measurements.
From photogrammetry to Lasergrammetry
In the case of some applications, photogrammetry is not suitable and requires the use of lasergrammetry.
For example, this is the case for smooth and homogeneous surfaces such as
steel or concrete, but also for complex geometries such as vegetation or utility networks.
This remote measurement technique makes it possible to control the
quality of a site but also to evaluate its damage by mapping it in real time using a drone equipped with LiDAR technology.
What is a Survey Drone?
Survey Drone is know as that type of drone used in surveying to be able to produce a map through the capturing of overlapping images.
They are specially and specifically built for surveying measurements and making of map in an unknown area of land.
The drone generates high-resolution orthomosaics and detailed 3D models of areas where low-quality, outdated or even no data, are available.
Also enable high-accuracy cadastral maps to be produced quickly and
easily, even in complex or difficult to access environments.
Is Drone Survey Accurate?
Accuracy: What does it mean?
To surveyors, “accuracy” refers to how closely a measurement or
observation comes to measuring a “true value,” since measurements and observations are always subject to error.
For a surveyor to be glad for a job well done, his measurements must be
very accurate which will determine the shape and topography of the area.
Accuracy in a ground survey is usually associated with the accuracy to
which the 3D data can simulate the real-world.
Is Drone Survey Accurate? Answer
Is Drone Survey Accurate? has been the question alot asks everyday.
One thing i am very sure is the accuracy of the drone when used in cadastral surveying.
The performance and type of drone, the quality of its components, the camera resolution, the height at which the drone flies, the vegetation, and
the method and technology used to geolocate the aerial images can heavily influence the accuracy of drone survey mapping.
At this point, it is possible to reach an absolute accuracy down to 1 cm (0.4 in) and 0.7 cm/px (0.3 in/px) GSD under optimal conditions
with a high-end surveying drone such as the WingtraOne.
What it means is that it gives almost 100% accuracy.
What are the benefits of drones in surveying?
Having answered “Is Drone Survey Accurate?” i will share the benefits.
In the evolution of the drone, the tech community is well aware of the benefits of UAVs in industries like construction, insurance, and real estate.
How businesses like those mentioned above, as well as those across other industries, utilizes drone as a survey tool is confusing.
Traditionally, survey data of a construction or urban development site.
These days, companies are recruiting the help of a drone for the same job.
All the survey tools now available as UAV accessories, it is clearer than ever that UAV’s are the fastest, safest, and most thorough option available.
Surveys conducted by drones are even more effective when companies are able to integrate their eyes in the sky with mapping software.
There are some ways the informations and analysis provided by Drones are helping users reach new heights in their logistics and business operations.
Automated mapping is the process of drawing maps in real time during a drone flight.
The Automated mapping is done using control points, which are
categorized as either known coordinates.
As the drone flies, it records images of the area below in both high resolution and infrared.
The imaging is then transmitted remotely and layered to map the area with extreme precision.
Cadastral surveying is a process which is very essential to real estate and construction and development industries.
In Casdastral, the drone’s survey capabilities are mostly to define
boundaries of homes either for rent or for sale, as well as subdivide
properties, record and acknowledge easements, and identify land massed and other impediments that affect land ownership.
The speed and accuracy of cadastral surveying using drones has huge implications on the real estate appraisal industry.
This is a classic adaptation of drone use by construction companies.
Equipped with volumetric mapping software, stock piles, material extraction pits, and spoil heaps are quickly and easily measured.
This process is made possible through the creation of a digital surface
Lidar Mapping is a means, by which complex measurements are taken to
create maps and scale figures.
A drone equipped with a laser measuring tool shoots beams at distant objects, and collects the reflected light with a sensor.
Using the elapsed time of a beam’s round trip, the Lidar drone is able to report extremely accurate data concerning distances and orientations.
What is the best drone for surveying?
At Aerotas our primary focus is processing the drone data that surveyors collect in the field.
Aerotas does not make any drone hardware, nor do we have an exclusive relationship with any drone manufacturer.
The Top five drones best for surveying are DJI Phantom 4 RTK,
DJI Phantom 4 Pro V2.0, DJI Mavic 2 Pro, Yuneec H520 + E90 and SenseFly eBee X + senseFly S.O.D.A.