Definition
SLAM, short for Simultaneous Localization and Mapping, is a technique that lets a device build a map of an unknown environment while at the same time figuring out where it is within that map. It solves two problems together: knowing the surroundings and knowing your own position in them.
SLAM is what allows a moving scanner, robot, or drone to explore a space it has never seen before and still produce a coherent 3D map. It works without relying on external positioning like GPS, which makes it ideal for indoor and enclosed environments.
In simple terms, SLAM is how a machine answers ‘where am I and what is around me?’ at the same moment, as it moves.
How It Works
A SLAM system continuously collects data from sensors such as lasers or cameras, along with motion sensors that track movement. As the device moves, it matches new observations against what it has already seen to estimate how far and in which direction it has travelled, while adding newly observed features to its growing map.
Because small errors can accumulate over distance, SLAM algorithms constantly correct themselves, often recognising previously visited places to close loops and keep the map accurate. The result is a consistent map and a reliable trajectory of where the device has been.
Applications
SLAM powers mobile mapping systems, autonomous robots, self-driving vehicles, drones, and augmented reality. In reality capture it enables handheld and backpack scanners to map buildings quickly as an operator walks through them, capturing indoor spaces where GPS does not reach.
Benefits
- Mapping without reliance on GPS or external positioning.
- Fast capture of indoor and enclosed environments.
- Real-time awareness of position and surroundings.
- Flexible use on handheld, backpack, and vehicle systems.
- A strong foundation for automation and reality capture.
Related Terms
- Mobile Mapping
- Point Cloud
- LiDAR (Light Detection and Ranging)
- IMU (Inertial Measurement Unit)
Frequently Asked Questions
What is SLAM used for?
It is used in robotics, autonomous vehicles, drones, augmented reality, and mobile mapping to build maps and track position at the same time.
Does SLAM need GPS?
No. SLAM is designed to work without GPS by using onboard sensors, which makes it well suited to indoor and enclosed spaces.
What sensors does SLAM use?
SLAM commonly uses laser scanners or cameras combined with motion sensors such as an inertial measurement unit to track movement.
What is loop closure in SLAM?
Loop closure is when the system recognises a place it has visited before, allowing it to correct accumulated errors and keep the map accurate.
About Track3D
Track3D helps teams turn mobile mapping and SLAM data into accurate digital twins and reality capture insights. Learn more at Track3D.
