I spent a lot of time this week on the design report, redoing our architecture figures to be more detailed and discuss through all subsystems. The report also gave me a chance to formalize all of the equations I’m using for my localization system, which will hopefully make it easier to explain and demonstrate how it works in the future.
I got a chance to implement the improved ToF-based ranging (with SIFS measurement including, as discussed in last week’s post) and even without angle, we seem to be getting close to the margin of performance which we expect. There’s currently an error a median error of around 1 m in both x and y, with some systematic bias based on where the access points are. I’ll be looking into the more extreme cases (namely the middle and bottom) to see if we can detect the faulty measurements that are contributing to the shift in position, either through restricting the SIFS measurements, restricting longer ranges (more likely to be NLoS), or balancing samples depending on the transmitter’s location at the time.
