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| HOW DOES LIDAR WORK? | |||||||||||||||||||||||||
| The concept behind LIDAR is fairly simple. A laser beam is emitted towards a target. The beam is scattered, or reflected from the target, and some of the reflected beam reaches back to the LIDAR that emitted the beam. The LIDAR unit then can calculate the distance of the target based on how long it took the beam to make it's trip. | |||||||||||||||||||||||||
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| The LIDAR emitts a laser beam towards the green target. | |||||||||||||||||||||||||
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| The beam travels to, and hits the green target. | |||||||||||||||||||||||||
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| The beam is scattered by the target. | |||||||||||||||||||||||||
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| Some of the scattered beam returns to the LIDAR | |||||||||||||||||||||||||
| The LIDAR has to make some very quick calculations to determine the distance of the targeted object. Let's say the green object in the pictures above is 300 meters from the LIDAR. | |||||||||||||||||||||||||
| c*t = 2d | |||||||||||||||||||||||||
| In the above equation, c is the speed of light, about 300000000 meters per second, t is the time it took for the laser to complete it's journey, and d is the distance between the LIDAR and the target. (You have to look at twice the distance, since the laser covers it twice. Once to reach the target, and once to return!) So if the laser covers a total of 600 meters at 3*10^8 meters/second, then it took the beam 0.000002 seconds to make it's trip. With only 2 microseconds of time between the emition and return of the laser beam, its a good thing the LIDAR can make the calculations for us! |
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