Deep Dive Into PulsedLight LIDAR-Lite V2 Device

LIDAR-Lite V2 Device is produced by http://pulsedlight3d.com/  This excellent device uses laser to measure the distance. The max distance is 40m. You can use it for both indoor and outdoor. And it is quite convenient to hook it up with open-source platform like Arduino. As the name suggested, its main usage is for LIDAR sensor. You can mount it to a robot or a drone to collect surrounding information. But people also use it for other purposes like generating point cloud.

This is what we see when open the device. Inside it has two parts: the upper part is the laser diode, which is the transmitter. The lower part is receiver, which can sense the laser light. It works like radar: the upper part sends a laser beam. The beam is reflected by object and the lower part detects the reflection. By correlating the signal sent and signal received, it can identify the peak of correlation and derive the distance based on the peak location. When the object moves farther, the reflection peak will be detected later. 

The SW library of LIDAR Lite allows to retrieve the correlation values. For each correlation, it has 256 elements. The plot below includes correlation of a few distance measurements. "corr50" curve has the max distance of 4.82m (482cm). Clearly the correlation peak occurs later for larger distance.