Photogrammetry vs LiDAR, which should you use?
When it comes to doing aerial mapping or surveying, the two most common methods are photogrammetry and LiDAR. While there are some similarities between the two, the methods used to collect the data are quite different and one may be better suited to your needs than the other.
What is Photogrammetry?
Photogrammetry is the process of taking a series of overlapping photos and stitching them together to form a single image. From the data, software algorithms can allow you to precisely measure the size, shape, and dimensions of objects, and even to create 3D models of an area. A big advantage of photogrammetry is that, since you are using actual photos, you get much finer details of objects and areas because of the visual camera.
Processing photogrammetry data has become extremely easy with tools such as Pix4D, DroneDeploy, and Maps Made Easy. These tools will process the data for you and give you an interface to do measurements and volumetrics.
Photogrammetry has many uses including cut/fill analysis, stockpile measurements, foresty management, land surveying, and much more.
Since the equipment to do photogrammetry is rather inexpensive, even being able to be done with many consumer-grade drones, it is very easy to get into doing photogrammetry.
What is LiDAR?
LiDAR (light detecting and ranging) sends down a laser pulse that is then measured by the return of the laser striking an object. The resulting output from LiDAR data is a point cloud that can have a very high level of accuracy.
Because LiDAR sends out extremely narrow beams of light, it can penetrate through vegetation better than photogrammetry. This can be very useful in getting “bare ground” measurements. If you are surveying a bare-earth construction site, LiDAR is not going to over any real advantage over photogrammetry. However, if you are working in an area with existing vegetation, LiDAR will usually produce much better results.
LiDAR equipment is much more expensive than simply using a standard camera, and processing of LiDAR data typically takes several different software packages, and is thus, much more complex to work with. Since the LiDAR equipment and workflow are much more intensive than photogrammetry, you really need to understand what each one delivers in order to make the best purchase decision.
Phantom 4 RTK
With a complete system costing under $10,000, the Phantom 4 RTK is designed for photogrammetry. While you “can” use some consumer-level drones, they will not provide the level of accuracy or the image clarity of the Phantom 4 RTK.
Matrice 300 / Zenmuse P1
When it comes to high-end photogrammetry, it is really hard to beat the combination of the DJI Matrice 300 and the Zenmuse P1 camera system. The P1 is a 48 megapixel, full frame camera that can actually “spin” around taking multiple images from different angles to dramatically increase the quality and accuracy of the data.
Matrice 300 / Zenmuse L1
The DJI Zenmuse L1 LiDAR system has brought the cost of equipment down significantly. Now, many companies can afford to have the equipment and expertise in-house, rather than having to outsource to a service provider.
Both Photogrammetry and LiDAR have their place in the mapping and surveying world, and your specific needs and requirements will determine which one is best for you.
To help you make your decision, reach out to our experts at firstname.lastname@example.org