How does a LiDAR sensor work?

A LiDAR sensor works by emitting pulses of laser light and measuring the time it takes for the light to bounce back. The LiDAR sensor then calculates the distance to the object based on the time it took for the light to return.

By rapidly emitting and measuring thousands of laser pulses per second, a LiDAR sensor can create a 3D map of the surrounding environment.

Here's how a LiDAR sensor works in detail:

1. Light Emission: 

   When the LiDAR sensor emits a laser pulse, it sends out a beam of light that travels through the air and bounces off objects in the environment. The light travels at the speed of light, which is constant and well-known.
   The laser pulse can be in the form of a single pulse or a series of pulses. The duration and frequency of the laser pulses can be adjusted based on the specific application and the requirements of the mapping project.

   The laser pulse emitted by the LiDAR sensor is usually in the near-infrared range and is safe for human exposure. The laser beam is focused to a very small spot, which allows for precise measurements of distances and the creation of high-resolution 3D maps.

2. Time Measurement: 

   It is through this process that the sensor determines the distance to objects in the environment.

   When the LiDAR sensor emits a laser pulse, it starts a timer. The light from the pulse travels through the air and reflects off an object in the environment, returning to the LiDAR sensor. When the light returns, the timer stops, and the duration of the timer measurement is recorded.

   This duration measurement is then used to calculate the distance to the object. Since the speed of light is known, the LiDAR sensor can calculate the distance based on the time it took for the light to travel to the object and bounce back.

   The LiDAR sensor is able to measure the time it takes for the light to return with great accuracy. This is due to the high speed of light and the high accuracy of modern timers. The combination of the two results in the ability to generate highly accurate 3D maps of the environment.

3. Distance Calculation:

   The LiDAR sensor uses the time measurement obtained from the time measurement process and the known speed of light to calculate the distance to the object. The formula used to calculate the distance is simple: Distance = Speed of Light x Time.

   The speed of light is a constant and well-known value, and is approximately 299,792,458 meters per second in a vacuum. The time measurement obtained from the LiDAR sensor is used as the time in the formula, and the distance to the object is calculated.

   The accuracy of the distance calculation depends on the accuracy of the time measurement obtained from the LiDAR sensor. Modern LiDAR sensors are able to measure the time it takes for the laser pulse to travel to an object and bounce back with great accuracy, which results in highly accurate distance calculations.

4. Data Collection: 

   The LiDAR sensor collects data on the distance to multiple objects in the environment, which is then used to create a 3D map.

   The LiDAR sensor emits laser pulses and measures the time it takes for the light to return, which is used to calculate the distance to objects in the environment. This process is repeated multiple times per second, allowing the sensor to gather data on the distance to multiple objects in a short amount of time.

   The data collected by the LiDAR sensor is stored in a digital format and can be processed using specialized software to create a 3D map of the environment. This map can be displayed in a variety of ways, including 2D maps, 3D models, and point clouds.

   The 3D map created by the LiDAR sensor provides a detailed representation of the environment, including the location and shape of objects, such as buildings, trees, and terrain. This information can be used for a wide range of applications, including autonomous vehicles, aerial mapping, and more.

5. Image Processing: 

   The collected data, which includes information on the distance to multiple objects in the environment, is processed using specialized software (such as ROCK Cloud). This software uses algorithms to analyze the data and generate a 3D image of the environment.

   The generated 3D image provides a detailed representation of the environment, including the location and shape of objects, such as buildings, trees, and terrain. The image can be displayed in a variety of ways, including 2D maps, 3D models, and point clouds.

   The software used for image processing can also perform additional tasks, such as removing noise or errors in the data, and refining the 3D image to provide even greater accuracy. Some software can also generate additional data, such as surface models, contour lines, and more, which can be used for further analysis and interpretation.

By emitting and measuring laser pulses, LiDAR sensors are able to gather precise and accurate data about the environment, making them useful for a wide range of applications, including autonomous vehicles, 3D aerial mapping, and more.