People counting

What is a Time-of-Flight sensor?

Time-of-Flight sensors can see the world in 3D. They do this by using reflections of infrared light to gather information about the distance of the objects in their Field of View.
Time-of-Flight camera Principle.png

Time-of-Flight sensors “see” by emitting pulses of invisible infrared light, then timing how long it takes for them to reflect off surfaces in the environment and return to the sensor. Because light travels at a constant speed, the amount of time taken for light to travel this distance is proportional to the distance the light has traveled — this is known as the Time-of-Flight (ToF) principle. (1) 

Measuring the time taken for an infrared pulse to return to the sensor enables a Time-of-Flight sensor to calculate the round-trip distance that the light pulse traveled, and hence the distance of the surface that the light reflected from.

What can a Time-of-Flight sensor do?

Time-of-Flight camera depth sensing

By measuring the distance of multiple points in its Field of View, a Time-of-Flight sensor can effectively take 3D snapshots of the world around it. In the data produced by a Time-of-Flight camera, the brightness of each pixel corresponds to the depth (or distance) of that part of the scene. 

Compared to other depth-sensing technologies (like structured light or stereo vision systems), Time-of-Flight sensors are relatively cheap. (2) They’re also versatile: because Time-of-Flight sensors detect the light they emit, they work perfectly in low-light conditions. 

Capable of frame rates more than 130 frames per second, Time-of-Flight sensors are ideally suited to real-time applications. In addition, small form-factors and low rates of power consumption mean that Time-of-Flight sensors can be easily integrated into a variety of different systems.

Time-of-Flight sensor applications

Time-of-Flight sensors are particularly well-suited to people counting applications. By quickly and accurately recognizing people entering and exiting, Time-of-Flight cameras can provide valuable occupancy data with none of the privacy concerns associated with other people counting technologies as they are fully GDPR compliant by design.

Introducing People Counting L-XL

People Counting L-XL from Terabee is a people counting device based on Time-of-Flight technology. Fixed above a doorway, the People Counting L-XL provides immediate access to valuable real-time occupancy data. 

By revealing exactly how spaces are used, the People Counting L-XL provides data that helps make spaces safer, more effective, and more comfortable. Applications include:

Lean Sensing Occupancy Monitoring

Crucially, the People Counting L-XL is intrinsically anonymous: low spatial resolution ensures that no personal identifiable information (PII) is ever captured, while smart onboard image-processing algorithms can still reliably count traffic with 98% accuracy or higher.

The People Counting L-XL features a wide 74° x 57° detection area, enabling it to monitor a 3.4 m wide area from a height of 4 m. Multiple devices can be easily synchronized to cover wider areas

Are you interested in finding out more about Terabee Time-of-Flight sensors? We’d love to hear from you. Get in touch with a member of our team today.

References and further reading

  1. Time-of-Flight principle (ToF): Brief overview, Technologies and Advantages. Terabee (2022)
  2. Pocket-lint. What is a ToF camera? Time-of-Flight sensor explained. (2021)

Related products

Terabee People Flow Counting L-XL

GDPR compliant people counting device. Optimize value and reduce costs from your retail operation, smart building or office space
Using advanced Time-of-Flight technology, Terabee People Flow Counting L-XL is GDPR compliant and provides accurate people counting data (98% accuracy or more) by monitoring the number of people entering and exiting doorways or corridors.

Easy to configure and install on high ceilings, the Terabee People Flow Counting L-XL fits any kind of wide indoor entrance, up to 15 meters in a multi-device setup. Our people counting algorithm is capable of filtering out static objects and counting multiple people passing in both directions below the device as they enter or leave a space.

The solution consists of an IoT people counting device and an optional IoT platform. Two product variations allow transmission of the data via Power over Ethernet or LoRaWAN. Interested? Contact us.

Terabee People Flow Counting M 2.0

Get real-time people counting data for single doorways and narrow corridors
Real-time data is the backbone of our modern, fast-paced world especially when it comes to monitoring space usage, occupancy, energy efficiency, security, building performance or tailored services. The Terabee People Flow Counting M 2.0 device is GDPR compliant by design, with a real-time data capability, providing seamless, accurate, and highly effective footfall measurement, at a competitive price.

Using Time-of-Flight technology, the People Flow Counting M 2.0 solution guarantees anonymity in its operations, prioritizing data privacy protection while offering robust, reliable occupancy monitoring.

People Flow Counting M 2.0 is the perfect addition to your Building Management System. The “smaller sibling” of People Flow Counting L-XL, People Flow Counting M 2.0 is designed for smaller doorways and narrow corridors. It comes in both Power over Ethernet (PoE) and LoRa models to best suit your needs.
My Cart