LiDAR stands for Light Detection and Ranging. This technology is utilizing light sensors to determine the distance that exists between the sensors and the target object. This is quite a popular remote sensing method that is being used out there. With the help of this technology, it is possible to effectively determine the elevation such as forest, ground, and buildings.
When you deep dive and take a look at LiDAR technology, you will figure out that it is using visible, ultraviolet, and near-infrared sources to proceed with sensing different objects. The light energy that is released out of the LiDAR system is called Pulse. On the other hand, light that is reflected from the targeted object is called a Return.
What is LiDAR?
Lidar is a type of technology that measures distance using the time it takes for a laser pulse to leave the device, bounce off an object, and return. In this way, Lidar can be used as a tool to make accurate maps. The word lidar is short for “light detection and ranging” which is basically what it does! Lidar works by sending out a light pulse from the device and then analyzing how long it takes for the return light to bounce back. This is done thousands of times in a row which produces a very accurate map of the surrounding area. Lidar is most commonly used in mapping situations where satellites are not available. A Lidar system can measure distances to objects at a distance greater than three kilometers (2 mi) or up to 30 kilometers (18 mi) with an accuracy of 10 centimeters (.4 inch).
The whole Lidar system is made up of four major parts. The first part is the rotating laser which emits light pulses to create a map of the surrounding area. The second part is the optical head, which captures the light signals and works to decode their information. The third part is the processor, which decodes the light signals received by the optical head and creates a picture of what it sees in 3D. This 3D image then goes into the final component which is called post-processing software that then creates an accurate GPS coordinate map.
How does LiDAR work?
Lidar works by sending out a pulse of infrared light from its device and then analyzing how long it takes for the return light to bounce back. This is done thousands of times which produces a very accurate map of the surrounding area. Lidar can be a complex technology to understand if you’re not familiar with it, but the process is quite simple. The device sends out a pulse of light which then bounces off an object and returns to the device. The time it takes for the light to depart, bounce off an object, and return to the lidar is recorded in milliseconds. This is then translated into a distance value. A computer is used to compare this measurement to the known distance of the object, which has been pre-calculated and recorded in the device. This comparison produces an overlaid image of where the object is located.
The most common type of Lidar used for mapping is known as a laser scanner. While there are many different types of Lidar, these cameras can measure distances up to 30 kilometers (18 mi) or more with an accuracy of 10 centimeters (4 inches). An example of a laser scanner type Lidar is the Light Detection and Ranging (LIDAR) system in an airplane.
The basic principles behind LiDAR are easy to understand and simple. As per this concept, you will be able to throw laser light into an object, which is located on the surface of the earth, and then calculate the overall time that it would take to return to the source. Based on the speed of light, the process will go ahead and measure the time that is taken. Along with that, it is possible to calculate the distance that exists between two objects. This is a relatively fast method available to determine the distance that exists between two objects. Due to the same reason, it is quite popular among analysts out there.
It is possible to use many different types of sensors for the development of a LiDAR network. Based on the specific type of sensor that is being used, the scanning units will be able to go ahead and fire a large number of pulses within a given second. It can be thousands of pulses. The sensor will then utilize the overall time that is taken for each pulse to come back. Based on this, the distance will be calculated. All the pulsed laser measurements will be able to end up delivering highly accurate measurements. Hence, it is possible to go ahead and use LiDAR without keeping any doubts in mind. It is also giving life to an excellent 3D visualization, which is called a point cloud.
Understanding LiDAR technology
The basics of LiDAR technology are easy to understand. It is using a pulsed laser to calculate the variable distances of an object from the surface of the earth. All these light pulses will be put together along with information that is collected via the airborne system. This will eventually give life to highly accurate 3D information about the surface of the world. Along with that, it is possible to get a clear indication of the target object as well.
You will be able to notice that three major components are responsible for enhancing the functionality of a LiDAR instrument. They include the GPS receiver, laser, and scanner. There are some other elements, which are playing a major role in the data collection efforts and the data analysis efforts. You will also be able to find optics and photodetector playing a major role. Many private and government organizations out there tend to use drones, helicopters, and airplanes to proceed with gathering LiDAR data.
Different types of LiDAR systems
We will be able to divide LiDAR systems into two main categories based on the functionality that they are delivering. They include terrestrial LiDAR systems and airborne LiDAR systems.
- Terrestrial LiDAR systems
The terrestrial LiDAR systems are installed upon vehicles that are moving. These vehicles are moving on top of the surface of the earth, which is assisting with the calculation of accurate data. The data collected by these LiDAR systems are quite useful at the time of observing the highways and analyzing existing infrastructure such as buildings.
- Airborne LiDAR
The airborne LiDAR systems are mounted on drones and helicopters, which are helping them to enhance the data collection speeds. Once the LiDAR is activated, it would emit light to the surface of the earth. It will be reflected from the objects on the surface and return immediately. This will eventually provide you the chance to get a clear measurement of the distance that exists between two points.
What are the applications of LiDAR?
One of the most common uses of Lidar is to create maps. This mapping process is very prevalent in areas with limited options for obtaining maps such as areas in Africa and Asia where Google maps may not be present. In these regions, maps are created using Lidar-scanning devices to produce detailed maps of the area.
To create a map with Lidar, the device must first be flown over the area that is being scanned. The device then captures image data from almost all angles, and measures exactly how far away the object is from the camera. To do this, it sends out a pulse of light which travels towards an object and then returns to its source. The distances between objects in each frame are recorded and stored, which will later be used to create a 3D representation of a map. Lidar can also be used in situations where GPS signals may not be accurate enough to use effectively in cars or other vehicles.
There are numerous applications associated with LiDAR as of now. Here are the most prominent applications out of them.
- Mapping
The most prominent application associated with LiDAR is mapping. It is possible to use this technology and go ahead with surveying in an effective manner. The surveying tasks would usually need to use 3-Dimensional measurements. LiDAR will be able to provide much-needed assistance with it. It would create a digital terrain model and a digital elevation model. This is quite helpful at the time of understanding the specific landscapes and precise information related to them.
- Architecture
We will also be able to see how LiDAR is being used for numerous applications associated with architecture as well. In other words, the applications of LiDAR are quite prominent at the time of constructing railways, road networks, and buildings.
- Real estate
There is a possibility to use laser scanners in indoor settings as well. This is a proven method that is helping people to go ahead and measure a space accurately. Along with the obtained measurements, it is possible to go ahead and create a highly accurate floor plan.
- Construction activities
LiDAR technology is quite helpful with construction activities as well. That’s because it is possible to use LiDAR technology to track building projects as well as procedures, which will eventually deliver digital twins for proceeding with BIM applications. On the other hand, they are in a position to assist with producing 3D models, which are quite effective at the time of monitoring the structures.
What are some benefits of LiDAR?
There are many different uses for this technology, but some examples include mapping forests and monitoring air pollution. Another benefit of lidar scanning is that it allows engineers to monitor any changes in the environment over time so they can better understand how our surroundings are changing. Lidar has become widely used in the past few years due to the incredible amount of detail it can provide. It is also used in applications like remote sensing, photogrammetry, 3D modeling for scientific research, and natural resource management. The lidar process can be done from a high position or a low position depending on the application. In almost all cases, the Lidar is mounted on a moving platform such as an airplane or car which makes it able to get more accurate information about specific areas. In some cases, drones are used which allow scientists to capture highly detailed images that would otherwise be impossible with other forms of technology.
What are some downsides of LiDAR?
Lidar, as with any technology, has some disadvantages as well. One downside is that if the weather is cloudy or it is very hot or cold outside at the time of scanning, the lidar beam may not be able to bounce back from an object. In these cases, Lidar can produce a less accurate measurement and it may not be useful.
Another disadvantage with Lidar is that it requires a lot of energy and batteries which can decrease its overall efficiency. The biggest disadvantage is that it requires a large amount of energy that can decrease its efficiency. However, with recent advancements in developing more efficient products that are solar-powered and use batteries to reduce weight and increase their efficiency, the technology has become very reliable as a do-it-yourself tool.
Recently there have been advances in developing more energy-efficient lidars that use solar power and batteries which reduces their weight and increases their efficiency.