Technology insights

Time of Flight principle

We specialize in optical Time-of-Flight (ToF). For range-finding, ToF is very powerful when emitting light rather than sound. Compared to ultrasound, it provides far greater range, faster readings, and greater accuracy whilst still maintaining small size, low weight and low power consumption characteristics.
structured light sensor camera

Time-of-Flight Principle: The basics

The Time-of-Flight principle (ToF) is a method for measuring the distance between a sensor and an object, based on the time difference between the emission of a signal and its return to the sensor, after being reflected by an object. Various types of signals (also called carriers) can be used with the Time-of-Flight principle, the most common being sound and light. TeraRanger sensors use light as their carrier because it is uniquely able to combine higher speed, longer range, lower weight, and eye-safety. By using infrared light we can ensure less signal disturbance and easier distinction from natural ambient light, resulting in the highest performing distance sensors for their given size and weight.

Time-of-Flight principle: Indirect ToF sensors

All-Time-of-Flight (ToF) sensors measure distances using the time that it takes for photons to travel between two points, from the sensor’s emitter to a target and then back to the sensor’s receiver.

Indirect and direct ToF both offer specific advantages in specific contexts. Both can simultaneously measure intensity and distance for each pixel in a scene.

Direct ToF sensors send out short pulses of light that last just a few nanoseconds and then measure the time it takes for some of the emitted light to come back. Indirect ToF sensors send out continuous, modulated light and measure the phase of the reflected light to calculate the distance to an object.
Direct And Indirect Time Of Flight

Time-of-Flight Principle Technology Comparison

depth sensing camera



This compact and affordable 3D Time-of-Flight camera is designed to support research, application developers and systems integrators in the fields of Smart Buildings, Automation, Robotics and more. Enable the third dimension with the cameras 80x60 pixel resolution and a wide 74° x 57° Field of View! It is easy to set up and to stream depth data via USB on Windows or Linux OS. An SDK and OpenNI code library is available to kick-start your application development.

Time-of-Flight applications

Time-of-Flight (ToF) depth cameras and sensors will enable you to measure volume, recognize gestures, capture movement and more.

Role of TOF cameras in people counting

Time-of-flight (ToF) cameras have proven a revolutionary concept in people counting applications worldwide. With the utmost precision guaranteed and unique considerations in place regarding personal privacy and data protection, ToF cameras can enable people counting solutions which offer superb insights into a variety of key business metrics, from periodic footfall to space optimization.
Terabee Real Time People Counting System

TOF Sensors to Provide Accurate Stock Monitoring

Continuously measure fill and stock levels of solid, powder or liquid materials using Terabee’s optical Time-of-Flight (ToF) technology - be it in silos, bins, tanks, stockpiles and more! Go for application-ready level monitoring products for quick installations and on-the-edge data computing
Silo Level Monitoring Solution

Time-of-Flight benefits

Time-of-Flight (ToF) is a powerful technology for accurate, affordable distance and depth-sensing technology.

Small and lightweight

TeraRanger tof sensors are the smallest size and lightest weight ToF distance sensors on the market at this performance level. (A TeraRanger Evo weighs just 9g!) This means that sensors can be placed in locations not previously possible when using larger, heavier sensors. For mobile robotics, including drones, this is a real advantage!

Long range

Despite their small size and light weight, TeraRanger tof distance sensors pack a powerful performance punch! TeraRanger Evo can measure distances at up to 60m range. And this is done with LED technology, not a laser! (See section on LED illumination.)

Fast refresh rates

TeraRanger tof sensors are optimized for high-speed readings. TeraRanger Evo 600Hz can measure FIXED 600 readings per second! In addition to being small and lightweight, high data refresh rates are central to our design ethos, making the sensors ideal for fast-moving applications, from mobile robotics to industrial automation and smart city applications like traffic monitoring and management.

LED Illumination

Instead of using laser emitters we use Infrared LED technology. This brings a number of important benefits.

Eye-safety: TeraRanger sensors remain eye-safe in all conditions, with no need for Laser Class 1 safety precautions!

Field-of-View: Rather than measuring a very small point, we can allow the emitted light to spread and form a Field-of-View. In many applications, this can be a distinct advantage. Imagine a sensor trying to detect a tree. With a laser, you might detect the leaves, or pass through the gaps and detect something much further away. In a robotics safety or anti-collision situation, this could spell disaster. With TeraRanger technology you are far more likely to detect the hazard you want to avoid. Generally, at 1m to the target, a TeraRanger One sensor is measuring an area approximately 4cm by 4cm.

Power consumption: Compared to some laser devices, LED’s consume far less power; something all users relying on battery-power will enjoy.

Easy to use

All TeraRanger sensors are plug and play. There is no customer calibration to do and no need to convert complex outputs into distance readings. TeraRanger sensors simply stream calibrated distance values in mm’s. We take care to compensate for environment variables, such as temperature and ambient light, automatically and instantly adapting to the conditions to provide the highest possible performance.

The sensors support multiple communication protocols and in most cases, when you connect the sensor, it will automatically recognize the host computers communications protocol (typically Serial/UART or TWI/I2C) and load the corresponding firmware.

Plug and Play support for multi-sensor, multi-axis use

Only TeraRanger technology provides a simple plug and play approach to multi-sensor applications. TeraRanger Multiflex for example provides 8 sensors connected to one flexible bus whilst the TeraRanger Hub Evo allows up to 8 TeraRanger Evo sensors to be connected, with the Hub centralizing power management, sensor synchronization and communications. Sensors can be placed in almost any direction, providing a fast and efficient way for clients to create custom arrays and configurations.

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