Firstly, it is essential to note that the point density of a project is dependent on the following listed factors:
- LiDAR scanner field of view
- Flight AGL (Above Ground Level)
- Flight Speed
- LiDAR Scan Rate
The swath length must be found to calculate the density of points LiDAR provides. Let’s consider this using the example of Livox AVIA, Figure 1.
Figure 1. Swath length for Livox AVIA.
The swath length is calculated using formula (1):
Where:
– Swath Length; AGL – altitude above ground level; FOV – LiDAR Field of View.
So, in this example, let AGL = 100 meters. Our swath length would be as follows:
= 100*(2*tan(35°)) = 140 m
Once our swath length is determined, we can find the point density of the scan using the following formula (2):
Where:
– Point Density (pts/m2); 
– LiDAR Scan Rate (pts/s); 
– Flight Speed (m/s).
So, for our example, let’s say we flew at five m/s, then our point density would be as follows:
Point Density = 240,000/(140*5) = 343 pts/m2
Now, using these formulas, you can calculate the point density for any lidar. Below are tables for Inertial Labs’ most common solutions:
RESEPI XT-32
FOV = 90o
Pulse rate, pts/sec | |||||||||
640000 | |||||||||
Flight speed, m/sec | |||||||||
5 | 10 | 15 | |||||||
Height (AGL), m | |||||||||
50 | 70 | 100 | 50 | 70 | 100 | 50 | 70 | 100 | |
Density, pts/m^2 | 1280 | 914.2857 | 640 | 640 | 457.1429 | 320 | 426.6667 | 304.7619 | 213.3333 |
RESEPI XT-32 | Pulse rate, pts/sec | ||||||||
1280000 | |||||||||
Flight speed, m/sec | |||||||||
5 | 10 | 15 | |||||||
Height (AGL), m | |||||||||
50 | 70 | 100 | 50 | 70 | 100 | 50 | 70 | 100 | |
Density, pts/m^2 | 2560 | 1828.571 | 1280 | 1280 | 914.2857 | 640 | 853.3333 | 609.5238 | 426.6667 |
RESEPI M2X
FOV = 90o
Pulse rate, pts/sec | |||||||||
640000 | |||||||||
Flight speed, m/sec | |||||||||
5 | 10 | 15 | |||||||
Height (AGL), m | |||||||||
50 | 100 | 150 | 50 | 100 | 150 | 50 | 100 | 150 | |
Density, pts/m^2 | 1280 | 640 | 426.6667 | 640 | 320 | 213.3333 | 426.6667 | 213.3333 | 142.2222 |
RESEPI XT-32 | Pulse rate, pts/sec | ||||||||
1280000 | |||||||||
Flight speed, m/sec | |||||||||
5 | 10 | 15 | |||||||
Height (AGL), m | |||||||||
50 | 100 | 150 | 50 | 100 | 150 | 50 | 100 | 150 | |
Density, pts/m^2 | 2560 | 1280 | 853.3333 | 1280 | 640 | 426.6667 | 853.3333 | 426.6667 | 284.4444 |
Pulse rate, pts/sec | |||||||||
1920000 | |||||||||
Flight speed, m/sec | |||||||||
5 | 10 | 15 | |||||||
Height (AGL), m | |||||||||
50 | 100 | 150 | 50 | 100 | 150 | 50 | 100 | 150 | |
Density, pts/m^2 | 3840 | 1920 | 1280 | 1920 | 960 | 640 | 1280 | 640 | 426.6667 |
RESEPI AVIA
FOV = 70o
Pulse rate, pts/sec | |||||||||
240000 | |||||||||
Flight speed, m/sec | |||||||||
5 | 10 | 15 | |||||||
Height (AGL), m | |||||||||
50 | 100 | 150 | 50 | 100 | 150 | 50 | 100 | 150 | |
Density, pts/m^2 | 342.755522 | 171.3778 | 114.2518 | 171.3778 | 85.68888 | 57.12592 | 114.2518 | 57.12592 | 38.08395 |
RESEPI XT-32 | Pulse rate, pts/sec | ||||||||
480000 | |||||||||
Flight speed, m/sec | |||||||||
5 | 10 | 15 | |||||||
Height (AGL), m | |||||||||
50 | 100 | 150 | 50 | 100 | 150 | 50 | 100 | 150 | |
Density, pts/m^2 | 685.511 | 342.7555 | 228.5037 | 342.7555 | 171.3778 | 114.2518 | 228.5037 | 114.2518 | 76.16789 |
Pulse rate, pts/sec | |||||||||
720000 | |||||||||
Flight speed, m/sec | |||||||||
5 | 10 | 15 | |||||||
Height (AGL), m | |||||||||
50 | 100 | 150 | 50 | 100 | 150 | 50 | 100 | 150 | |
Density, pts/m^2 | 1028.267 | 514.1333 | 342.7555 | 514.1333 | 257.0666 | 171.3778 | 342.7555 | 171.3778 | 114.2518 |
OUSTER OS1-64
FOV = 45o
Pulse rate, pts/sec | |||||||||
2621000 | |||||||||
Flight speed, m/sec | |||||||||
5 | 10 | 15 | |||||||
Height (AGL), m | |||||||||
50 | 100 | 150 | 50 | 100 | 150 | 50 | 100 | 150 | |
Density, pts/m^2 | 12655.3075 | 6327.654 | 4218.436 | 6327.654 | 3163.827 | 2109.218 | 4218.436 | 2109.218 | 1406.145 |
IMPORTANT! The data provided may differ from the actual data since the density of dots is also affected by the material and color of the object. For example, the density values will be lower for black asphalt or black cars.