UWB ToF Calculator: Time of Flight Distance Formula & Tool

This UWB Time of Flight (ToF) calculator allows you to compute distance based on the Two Way Ranging (TWR) formula. By inputting the Round Trip Time (RTT) and Processing Time, you can determine the distance in meters.

UWB does not measure distance directly; it measures Time. Because radio waves travel at the speed of light, if we know exactly how long a signal took to get from Point A to Point B, we can calculate the distance. Since UWB pulses are extremely short (nanoseconds), we can measure this time with incredible accuracy.

Example Calculation Values

Scenario Example:

Let’s imagine you are unlocking your car.

• Device A: Your Car (The Initiator).
• Device B: Your Smartphone (The Responder).
• Speed of Light (c): Approximately 299,792,458 meters per second (m/s), Approximately equals 3 x 10^8 m/s.

INPUTs:

• Round Trip Time (RTT), ns = 5020 ns
• Processing Time, ns = 5000 ns

OUTPUTs:

• Time of Flight (ToF), ns = 10 ns
• Distance, meters = 2.99792458 meters

_Image Courtesy : FiRa Consortium, Inc. _

UWB ToF and Distance Formula

The Formula: Two-Way Ranging (TWR) In the real world, devices (like a phone and a car) do not have atomic clocks synchronized perfectly. To solve this, UWB uses Two-Way Ranging.

1. Device A sends a signal (Poll).
2. Device B receives it, waits a specific time, and sends a signal back (Response).
3. Device A receives the response.

Conclusion

This UWB ToF calculator provides a practical way to convert time measurements into distance using the principles of Two-Way Ranging. By understanding and applying these formulas, you can achieve precise distance calculations essential for various applications in wireless communication and positioning systems.