LIDAR TECHNOLOGY
LIDAR technology, which stands for Light Detection and Ranging, uses sensors that emit laser beams that shoot down to the ground and bounces back. The distance of the laser and back to the sensor is then measured and recorded.
This technology is currently used for creating super detailed 3D maps and models of landscapes, buildings, and human-made objects, which then opens the floodgates for a whole new range of creative possibilities when it comes to planning and innovation.
Is It Better than Photogrammetry?
Up until now, photogrammetry has been used to carry out this and similar tasks while surveying areas. However, the two are very differents. Photogrammetry uses photographs (as the name suggests) to try and measure the distance between two different objects or points, whereas LIDAR uses lasers, which is simply far more accurate.
LIDAR can even go as far as detailing when vegetation appears on the ground and how dense it is, which is a technology previously non-existent and would take countless man-hours to incorporate into planning. However, what really brings LIDAR into the limelight is the level of accuracy it can provide. In fact, in high-fidelity modes, a LIDAR drone can provide detailed information of 100-500 data points per square meter with an impressive accuracy of 2-3 centimeters. This is previously unfathomable.
How is LIDAR Data Collected?
When surveying an area of land, the operator of the drone needs to ensure that a flight plan is developed where you can get an ample number of overlaps to ensure the ground is properly covered and the lasers can penetrate vegetation properly and accurately.
There are a ton of different factors that also need to be considered, including the altitude, speed, and line spacing, as well as other factors like weather conditions and structures present within the area.
Man-made structures, such as buildings or towers, tend to absorb a lot of light and can dramatically affect how the laser is bounced back to the sensor. This has resulted in flight plans needing to be adjusted since more accurate readings can only be collected when flying at lower altitudes.
When using LIDAR technology yourself, it’s important to ensure that you’re using the technology in a cost-effective way since it can be expensive if not managed properly, especially when you consider the price of drones and unmanned aircraft technology. Nevertheless, LIDAR technology has proven to be effective in both one-time applications and extensive, long-term projects.
How is LIDAR Being Used?
As LIDAR is optimized and innovated upon, more and more uses are being discovered all the time, and, as the title suggests, it’s true that the technology is really changing the game for industries around the world.
For example, drones are being flown over certain areas, and resulting maps are being developed to highlight, survey, and monitor grounds where assets such as towers and wind turbines could and have been built. In areas that are prone to flooding, LIDAR is being used to provide much improved accurate measurements that can help improve risk assessment outcomes and enhances the ability to create more effective emergency planning processes.
In areas of the world affected by drought, the vegetation density technology is being used to improve drainage systems that allows water to be used more efficiently.
As you can see, there’s a lot that LIDAR can provide, and this is only going to expand over the coming years as the technology gets better and more renowned. There are practically no limits to where LIDAR can go, and it’s definitely interesting to think about how it will be used in the future.
Processing drone survey data
While surveying with drones, images of the ground are taken from multiple vantage points. Through processing these images, a photogrammetry software can then create orthomosaics and 3D models, from which it can measure accurate distance, as well as surfaces and volumes of physical objects.
Data outputs from the drone
Images taken by the drone are usually saved on a memory card (such as SD card), just like for any other camera. Depending on the technology used by the drone, the images are already geo-tagged or can be imported in a geo-tagging software. According to the size of the survey site, you probably have between a few hundred images and a few thousand, and each image contains geographical information (X, Y, Z).
Importing into a photogrammetry software
After importing or uploading the geo-tagged images in a photogrammetry software such as Drondeploy, delair.ai, 3DR Sitescan or Pix4D, images will be stitched together to create 2D or 3D models of the surveyed site. Image processing can be a lengthy process depending on the number of images and the performance of your computer. Some photogrammetry software are desktop-based, thus requiring robust hardware. Other software is cloud-based, employing powerful servers instead of your local computer to process the data.
What is the difference between lidar and photogrammetry?
Since some aerial survey drones can now carry LIDAR sensors, what is the right choice between a LIDAR and a photogrammetry payload? It all depends on the specific use. Find out how these two technologies work, their features, and the most suitable for your project
LIGTH DETECTION AND RANGING
ACCURATE
MEASUREMENT
100-500 DATA POINTS PER SQUARE METER
CREATE 2D OR 3D MODELS
Drone Flight Training & Data Analysis