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How a Smartwatch Measures Distance and Speed With/ Without GPS

Smartwatches these days are available in all price brackets. Even if you were to spend less than 5000 INR/$60, you could still end up with a good fitness tracker. But if you look closely at the spec sheet, you might not see a GPS sensor listed. Yet, the device boasts of features that can help you track your walk and provide you with all related data. So, how a smartwatch measures distance and speed with or without a GPS sensor? Read our article to find out!

Smartwatch Recording Distance and Speed

How a Smartwatch Measures or Records Distance and Speed?

An accelerometer is a sensor that tracks distance without a GPS sensor. The majority of fitness bands and wearables rely primarily on accelerometers for operation. Accelerometers are sensors that keep track of your body’s motions by recording the number of steps you take over time. Additionally, this sensor monitors your sleep at the same time. While you sleep, the sensor monitors your motions.

How Does An Accelerometer Work?

Accelerometer To Measure Distance in Smartwatch

A MEMS-based circuit known as an accelerometer senses or measures the forces of acceleration brought on by movement or tilting induced by gravity. It can gauge the movement or acceleration of the associated device. It can detect movement along the X, Y, and Z axes.

The software on smartwatches employs algorithms to examine the accelerometer’s raw data and decide what constitutes a step. The frequency and amplitude of the 3D accelerations and the patterns of stepping bouts and pauses are only a few of the data aspects that may be considered.

Each software uses a unique algorithm and threshold to determine which actions are eventually classified as steps. As a result, for the same activity, various trackers might provide a range of values.

How Smartwatch Measures Walking Distance

When a person walks, they bounce slightly with each step. Watch the top of a person’s head as they walk away from you. Their head, torso, and hips are synchronized in a smooth bouncing motion. While people don’t bounce very far, only one or two centimeters, it is one of the clearest, most constant, and most recognizable parts of a person’s walking acceleration signal.

With each step, a person bounces up and down in a vertical direction. If you are walking on Earth (or another big ball of mass floating in space), the bounce is conveniently in the same direction as gravity.

We will count steps using the accelerometer to count bounces up and down. We will utilize gravity to determine which direction down is because the watch may rotate in any direction. By calculating the number of bounces in the direction of gravity, a pedometer may track the number of steps taken.

Once the distance is measured, it uses the time to calculate the speed and then provides it to you. This is how smartwatches measure distance and speed without GPS.

How Does GPS Sensor Help In Measuring Data?

Dual Band GPS Smartwatch

GPS sensors these days are being made available on smartwatches as well. Like on your phones, this helps you provide direction and measure distance in your activities. A smartwatch’s ability to independently provide navigation data is quite convenient for many people.

With a GPS smartwatch, you can track and map your route, distance traveled, and speed while doing any activity such as running, walking, cycling, climbing, etc. It can also help determine elevation while hiking or trekking.

There are a few inaccuracies involved when it comes to measuring distance solely from an accelerometer. For example, it might take into account some micro movements as steps, and these errors compounded over time might lead to larger inaccuracies in the health data.

Therefore, using a GPS sensor might help bring down these inaccuracies and can help track your data in a much better way. It can also provide details about the path covered and improve the accuracy regarding speed, step length, and, eventually, the distance covered.

Overall, an added GPS sensor will help you improve the accuracy in position, leading to a more accurate step length and, therefore, a more accurate count of the step data. This will then improve the accuracy of the other details like the calories burnt, speed, step goals, etc.

Related | How a Smartwatch Detects Motion, Steps, or Calories? Improve Accuracy

Tips to Increase Smartwatch Distance Tracking Accuracy

The accuracy of your smartwatch step tracker generally depends upon the watch’s hardware and how the software works in avoiding false detections. You can follow the tips below to make the smartwatch or band detect your steps more accurately.

  • Use Non-Dormant Hand: Your dominant hand, i.e., the one you use to do most tasks, stays more active throughout the day. You end up doing tasks like stirring the curry or putting the nail on the wall, which can cause false detections. So, avoid wearing the watch on your dormant hand.
  • Wear it tight: Wear the smartwatch or fitness tracker firmly. It should not be loose or hanging around. Otherwise, it may result in inaccurate readings for heart rate and blood oxygen.
  • Manual or Automatic Detection: Some smartwatches feature automatic detection for workouts and activities. If your watch records normal activities such as walking or running, consider turning off automatic detection.
  • Calibrate Stride Length: Some watches from brands like Fitbit let you calibrate or manually enter the stride length. Go to a place you’re aware of the distance. Count your steps as you cover the distance. Then, divide the distance traveled by the number of steps to find your Stride Length.

Wrapping Up

This is all you need to know about how a smartwatch measures your distance and speed with or without a GPS sensor. We hope you found this article to be informative. Anyways, does your smartwatch have a GPS sensor? Let us know via comments. Stay tuned for more such articles that will explain finer details of smartwatches and wearable technologies in general.


Supreeth Koundinya