Why Sports GPS Watches May Show Oversized Results?

Sometimes the values ​​issued by an electronic watch with a GPS tracker can confuse their owners, since the values ​​issued by them will differ significantly from the actual values ​​calculated in advance when choosing a distance for running.

A number of factors that do not allow determining the exact location can lead to errors, among them: an increase in the angle of deviation from the distance, forced breaks, the need to overtake rivals. However, according to studies conducted by scientists from Austria and the Netherlands, even without taking into account the above factors, sports GPS watches may give incorrect results.

The principle of operation of GPS equipment is based on the interaction of the satellite with an electronic clock or smartphone, which is a must-have accessory while jogging. In accordance with the data obtained in the studies of Peter Rancher, this interaction is not a constant process, but more like frequent intermittent cycles.

As Peter Renecher replied in an email to Runner's World:

“When you take a GPS navigator with you, you compose a trajectory of movement on the ground for it. The trajectory should include positions connected in series (points on the map). ”

According to Mr. Renecher, errors are inevitable, since GPS equipment registers your movements in space in an intermittent mode, only from time to time fixing your location points, and then connecting them into segments, forming your path.

Error No. 1 is called interpolation. If your GPS sports watch for running doesn’t fix the points of your movement in space often enough, underestimation of the distance that you have covered can occur.

As Peter Renecher told us: “Let's imagine that you are running a circular distance, and during this time the navigator will register your trajectory only at 4 points, what will happen?” Instead of the expected lap distance, it will become square. ”

Error No. 2, the more common, is called a measurement error. Each time, when a satellite tries to contact electronic equipment, the signal may go sideways, showing a location that is slightly not true. When your watch or smartphone is trying to measure the distance between the last two control points, the distance will be greater than what you actually ran. These small errors will ultimately lead to overpriced results.

As Renecher explained:

“The problem is this: if your GPS-navigator picks up more positions, then the path will be longer, if less, then it will be shorter.

In his opinion, and the opinion of co-researchers, the use of GPS equipment in any case is associated with an overestimation of the results even despite the fact that many navigator models can accurately capture satellite signals based on its location.

According to Mr. Renecher, according to the results of his research, published in one of the international publications “Geographical Sciences” (International Journal of Geographical Information Science), a volunteer with a tracker who recorded movements every second in several series of studies, the deviation in the indicators was 10% .

He said: “We deliberately used a very poor quality device to make the error in operation more pronounced,” since there should be fewer errors in more advanced models, but they still exist. ”

According to Renecher and his assistants, there is a solution to the problem, and it is subject to the laws of mathematics.

It turns out that every time a satellite establishes a connection with your watch or smartphone, it registers your speed and your location. According to Reneecher, measurements of speed indicators are usually very accurate and do not affect the overestimation of values, so one of the possible solutions to the problem is to collect information about the change in speed and calculate the distance through this indicator.

Although mr. Renecher agrees that the hypothesis he proposed requires verification; he insists on including the speed indicator in the distance calculation formula. According to Renecher, you don’t need to purchase new GPS watches, but just update the software in them.

But despite a deep immersion in the problem associated with GPS-systems, Renecher remains a loyal advocate of GPS technology. According to him, GPS is a fantastic system, although the quality of information collection and distance measurement requires elaboration and improvement.

Source: http://www.rafiqsonsonline.com/product-category/citizen/