Incorrect distance

[lakshmanpasala]

I am using Kontakt beacons for testing and have changed the txPower to -69 as that is the default values for Kontakt. But for beacons that are placed at 5m the my values range from 11-45m with a median of 18m. Interestingly the closer the beacon is from the device the more accurate my values are for the distance.

Is there a way to get correct distances for beacons placed at about 5-10m?

[pwittchen]

Hi,

Thanks for reporting that issue. I've seen the similar problem. I think it may be related to the hardware. As you noticed, when the device is close to the beacon, distance is calculated correctly. Maybe it requires a separate calculation formula for longer distances? You can check, how it behaves with official SDK provided by the Kontakt. If official SDK also returns incorrect values, you can report it to the support of the Kontakt company. Exact formula for calculating distance is here: https://github.com/pwittchen/ReactiveBeacons/blob/RxJava1.x/library/src/main/java/com/github/pwittchen/reactivebeacons/library/Beacon.java#L72

Regards, Piotr

[lakshmanpasala]

The issue was not with the formula but rather the device and environment noise. Since my use case was indoor navigation, I had account for the noise in the RSSI values using Kalman Filter and some other statistical models and then use the formula to get distance. This at least ensured that even though the values were not accurate but they were relatively correct while dealing with multiple beacons.