Interesting in the lidar and 3d scanner technology. Maybe, you want to buy one, or you want to know what is best for you. So, In this article, I will explain to you the concepts of the 3d laser scanner and which one you have to pick.
before going deep into the definition of 3d lidar scanner. We will understand one main component of 3d laser scanner. Is a lidar. What is a lidar and how can we define it?
the lidar is defined as a laser system that sends high-frequency impulsions, that finally get reflected by an attacked object.
the lidar knows the distance by calculating a time of back and forth of the impulsion invited. Then with a determined speed. he can get a precise distance.
HOW MANY TYPES OF 3D LIDAR SCANNERS
There are two main types of lidar scanners each one has its technology.
TOF lidar: TOF is an abbreviation of ” TIME OF FLIGHT “. The “Tof lidar” is based on the time calculation of a wave. In other words, It calculates the time of back and forth of light emitted.
theses types of lidars are mostly used for terrestrial scanning operations, like scanning building and geology monuments…
CW LIDAR: Or constant wave, these types of lidars send a dephased impulsions with slow better performance than the previous one the “TOF LIDAR”. it used for aviation safety, wind power generation, atmospheric dynamics …
after talking about lidar and its characteristics now we can go ahead and talk about the 3d lidar scanner
What is 3d lidar scanner?
a 3d laser scanner is a material with function-based, on rayonnant emission with a very tiny bean wave.In conclusion,this system has 5 main components :
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–laser or lighting source
–GPS or positioning system
–IMU inertia mesurment unit
components of 3d laser scanner
- laser or lighting source:
the laser is a tiny beam of light that generates a lidar. So this light reflects from objects and gets back to be analyzed by a center measurement.
the laser sends millions of beams per second in 3 dimension space. Then, collects the reflected beams to form a 3d map. this operation base on emission and reflection.
- calculation center :
the calculator center is an electronic device that calculates and controls the time between the invited and returned pulse. That is to say, His job is to record the exact time to offer and accurate data.
with a million operations per second, the timer (calculator center) has a primordial job of the scanning operation.
- IMU inertia mesurment unite
the inertia measurement unite is a system that measures the velocity, orientation, and gravitational forces. This system contains some tools like an accelerometer, gyroscope, and magnetometer sensors, all these tools are essential to determine the position of the lidar because the lidar isn’t in a fixed position, is continually moving in different positions, it dependable on its holder maybe human, plane or car …
In order to ensure the correcte distance, the inertia measurement must provide accurate information.
- GPS or positioning system
the role of the GPS system is to record the coordinate (x,y,z) of the scanner. Which means determine the position of the scanner. The GPS allows referencing the coveted spots in a map and finally to get a precise geometrical map.
the computer is a device that controls all these units, their functions, coordinations between these components. In general, it has software that receives and analyzes all the collected data.
TYPES OF 3D LASER SCANNER
there is a variety of 3d scanners each one has its own qualities and specifications. It also depends on the environment where we want to work or scan. Scanning building is very different from scanning jungle lands. So, technology change and depend on the nature of applications. Therefore we will note different types of laser scanners.
MULTI ECHO 3D LASER
These types of laser are capable of generating one wave that can have multiple reflections at the same time. These reflections are called echos. That means when a beam of light arrives at a certain point. As result, it can reflect from it or penetrate it or it gets reflected from the second parallel point. This image is showing more details about this process.
the multi-echo 3d laser scanner. On the other hand, and for most cases is specialized for scanning high density and complex surfaces like jungles and all frosty applications
SIMPLE ECHO 3D SCANNER
versus the multiple echo 3d scanner. A simple echo 3d scanner is based on a simple principle, one reflection by one emission.
That means, once the beam of light goes, it reflects directly from the object without penetrating it. It a simple operation, versus the multiple echo scanner. The simple echo 3d scanner measures the time between the back and forth of the signal. Without requiring a lot of effort to analyze a ton of data.
this kind of 3d scanner is mostly used in terrestrial applications like building scanning, geology monument scanning, etc.
what to choose for a 3d lidar scanner?
The question depends on the application for what want to use. If the use of a scanner will be for the simples and non densest spots, like building, simple geology monuments …etc.Then the lidar simple echo will be enough useful for the scan.
In reverse, if we have a high-density spot like land jungles, complex spaces. Then we can talk about the multi-echo lidar for use.
TROUBLES OF 3D SCANNERS
one of the problems that can put this technology in trouble and infect the quality of scanning is climatic conditions.
snow: the lidar or a 3d laser scanner sometimes could have some troubles with reflection. that mean the laser impulsion might be reflected on snowflakes and getting the wrong data to analyze
rain: the waterdrops could produce some problems with light reflection, the light can deviate when it hit these drops causing a loss of data to analyze and precision.
the technology lidar actually has wide use and applications in many industrial sectors like
Automobil: at this moment, this technology is integrated into so many domains and industries. It helped and made it so much easy for car drivers to have some kinds of release and comfort.
In high ways. The driver could let the car drive by itself without any intervention or control. As a result, the Lidar system scans the environment. The system build a map that allows him to make a decision of turning left or right or breaking to prevent a possible accident.
Agriculture: The lidar helps agriculture companies to pinpoint areas and spots with a high density of light. For more efficient growing…
Astronomy: NASA uses the technology lidar to explore mars. So, the lidar allows them to create a topographic map of the red planet
This lidar technology will make a big revolution, thank to stem research in almost all domains it will allow humanity to discover more about nature where they live. As a result, take much control and advantage of it.