LiDAR (Light Detection and Ranging) has become an essential sensing technology in robotics, autonomous vehicles, and smart infrastructure. As the demand for spatial awareness grows, understanding the differences between single-line LiDAR and multi-line LiDAR is crucial for choosing the right solution.
This article explores their distinctions across scanning dimensions, performance, use cases, and cost—helping you make informed decisions for your project.
1. Scanning Dimensions and Point Cloud Density
Single-Line LiDAR: 2D Plane Scanning
Single-line LiDAR emits a single laser beam that performs horizontal (2D) scanning. The resulting data is a flat plane of point cloud information, which lacks vertical height measurement. While limited in dimensional sensing, it effectively detects ground-level obstacles—ideal for basic navigation and collision avoidance.
Multi-Line LiDAR: Rich 3D Environmental Awareness
Multi-line LiDAR, on the other hand, emits multiple beams (e.g., 4, 16, 32, or 64 lines), enabling the capture of layered 2.5D or full 3D point cloud data. It allows precise measurement of object shape and height, significantly enhancing the system’s ability to perceive and reconstruct complex environments.
2. Application Scenarios
Single-Line LiDAR: Compact Robots and Indoor Navigation
Due to its compact design, fast response time, and affordability, single-line LiDAR is frequently used in:
Service robots (e.g., vacuum cleaners, delivery robots)
Indoor SLAM (Simultaneous Localization and Mapping)
Light-duty obstacle detection
It is especially popular in consumer electronics and entry-level robotic systems.
Multi-Line LiDAR: Autonomous Driving and Industrial Robotics
Multi-line LiDAR provides the detailed spatial perception required for:
Autonomous vehicles and driver-assistance systems
Outdoor robotics and drone navigation
Infrastructure monitoring and 3D mapping
Its ability to detect moving and static objects in dynamic environments makes it indispensable in high-stakes applications.
3. Performance Comparison
| Feature | Single-Line LiDAR | Multi-Line LiDAR |
|---|---|---|
| Scanning Type | 2D (Horizontal only) | 2.5D to 3D (Multiple layers) |
| Resolution & Detail | Lower, suitable for basic obstacle detection | High-density point cloud with object profiling |
| Response Speed | Fast, lightweight | Slightly slower due to higher data processing load |
| Data Volume | Low, easy to process | High, needs powerful computing |
Single-line LiDAR offers high scanning frequency and lower computational overhead, whereas multi-line LiDAR delivers better environmental understanding at the cost of higher processing demand.
4. Cost and Physical Considerations
Single-Line LiDAR: Budget-Friendly and Lightweight
Price: Typically under $100 in bulk
Size: Small and lightweight
Manufacturing: Simpler components, easy integration
Multi-Line LiDAR: High-End, Complex Systems
Price: Ranges from hundreds to thousands of dollars
Size: Larger and heavier
Manufacturing: Involves complex components like rotating mirrors, MEMS, or Flash systems
While multi-line LiDAR delivers superior performance, its higher cost and bulkier design limit its use to advanced applications.
5. Underlying Technologies
Single-Line LiDAR
Commonly based on triangulation or Time-of-Flight (ToF) principles, single-line LiDAR sensors are known for:
High stability in distance measurement
Strong resistance to ambient light interference
Multi-Line LiDAR
Multi-line LiDAR systems use a combination of:
Multiple laser emitters and receivers
Rotating mirrors or advanced solid-state tech (e.g., MEMS, OPA, Flash arrays)
These technologies enable wide-angle scanning and depth-rich 3D data acquisition.
Which One Should You Choose?
| Use Case | Recommended LiDAR Type |
|---|---|
| Cost-sensitive consumer robots | Single-Line LiDAR |
| Indoor mapping and navigation | Single-Line LiDAR |
| High-resolution 3D mapping | Multi-Line LiDAR |
| Autonomous driving systems | Multi-Line LiDAR |
| Lightweight embedded systems | Single-Line LiDAR |
| Outdoor or complex environments | Multi-Line LiDAR |
Conclusion: Precision or Practicality?
Both types of LiDAR serve valuable roles, but their suitability depends on your application’s complexity, budget, and technical requirements. Single-line LiDAR is ideal for straightforward 2D applications with tight cost and space constraints, while multi-line LiDAR excels in delivering detailed 3D spatial awareness for advanced robotics and autonomous systems.
If your project involves service robots or indoor mapping, a cost-efficient single-line unit may suffice. For cutting-edge technologies like self-driving vehicles or smart cities, multi-line LiDAR remains the gold standard.
