Lidar, which stands for Light Detection and Ranging, is a remote sensing technology that uses laser light to measure distances and gather information about objects and their surroundings. It operates on the principle of reflecting laser pulses off target objects and analyzing the returned signals.
The basic working principle of lidar involves the following steps:
Emitting laser pulses: A lidar system emits short and intense laser pulses in a specific direction.
Pulse propagation: The emitted laser pulses propagate through the air or another medium, such as water or fog, towards the target objects.
Reflection and scattering: When the laser pulse encounters an object, it interacts with the surface, causing reflection and scattering of the light. Some of the light is reflected back towards the lidar system.
Detection of reflected light: The lidar system has a detector that receives and measures the intensity of the reflected light.
Time-of-flight calculation: By precisely measuring the time it takes for the laser pulse to travel to the object and return, the lidar system can calculate the distance to the object.
Data processing: The collected distance measurements are combined to create a 3D representation of the object or the environment.
Regarding your second question, lidar operates using laser light, which is an electromagnetic wave. Unlike RADAR (which uses radio waves) or sonar (which uses sound waves), lidar's laser light can be affected by reflection and refraction when passing through transparent materials like glass. When a lidar pulse encounters a glass window, part of the pulse may reflect off the window surface, while another portion may enter the glass and undergo refraction.
The interaction of lidar with glass windows can cause some challenges and limitations. Reflections from glass surfaces can generate unwanted echoes or distortions in the lidar data. Additionally, the refractive properties of glass can alter the direction and speed of the laser pulse, potentially affecting the accuracy of distance measurements.
To mitigate these effects, lidar systems may employ specific techniques or algorithms to account for glass reflections and refractions. Some advanced lidar systems use multiple wavelengths or polarization techniques to distinguish between reflections from glass and other objects. However, it's important to note that the specific performance and limitations of lidar systems when interacting with glass may vary depending on the system design and operating conditions.