Long Range Distance Measurement

[ptejasv]

Hello and thank you for your help.

I am working on a project that uses distance measurements (DM). According to the Introduction to Nordic Distance Toolbox webinar, the largest distance tested was around 18m with a standard deviation of 37cm using high precision. Could I check if there is a theoretical maximum distance at which DM will work with similar accuracy?

I found some articles that have tested that the BLE range of the nRF DKs can be well over 500m (https://devzone.nordicsemi.com/nordic/nordic-blog/b/blog/posts/testing-long-range-coded-phy-with-nordic-solution-it-simply-works-922075585). Should DM work at similar ranges or is there a point at which the accuracy diminishes?

I'm currently working on the nRF52840 DKs, using nRFConnect SDK v2.2.99. The code I am running is the sample code for distance measurements modified to output high precision results only.

Thank you.

[Simonr]

Hi

We have not done any tests with the Distance Toolbox in terms of maximum range. The deviation of distance measurements must be expected to increase with distance, as there will be more interference from more sources the further away you get. The range you'll be able to achieve and quality of the signal is mostly dependent on the environment you're deploying the devices in, and testing should be done in similar environments to get reliable test results. 

I personally would not expect better accuracy than 1m at 100m range in a no to low noise environment, but this is mostly educated guessing on my end. At 500m you should be able to keep a BLE connection in a low noise environment, but the distance measurement will likely not be very reliable.

Best regards,

Simon