DS-TWR Range Analysis

Hi all,

I plot the distribution of measured error over several distances (1000 samples in each distance) using DWM1001C in LOS conditions and this is the result:

image

So for the SS-TWR, it is normal the error increase with the distance which seems normal.
but with DS-TWR, it the opposite wich seems weired to me.
Any explantation please ? or is it normal ?

A 1m difference in distance makes a big difference in signal power at short ranges but not much difference at longer distances. This means that short ranges are more prone to RSSI correction errors than long ranges.
I don’t know if this entirely explains the curve seen but it would give a curve similar to what you see.

@AndyA thank you for your response.