I have been attempting to track down measurement issues in our system and so have started simplifying everything to a minimum case and am still seeing significant measurement errors when the distances are being reported as closer than they actually are.
For the minimum test case setup I have taken two MDEK1001 kits and set them as anchors and placed them 1m apart. I then took another MDEK1001, set it as a tag at 1m from on of the anchors and used the les command to record data. Here is what it looks like:
C084[0.00,0.20,0.66]=0.88 5433[-0.75,0.00,0.66]=1.92
C084[0.00,0.20,0.66]=0.89 5433[-0.75,0.00,0.66]=1.92
C084[0.00,0.20,0.66]=0.92 5433[-0.75,0.00,0.66]=1.85
C084[0.00,0.20,0.66]=0.92 5433[-0.75,0.00,0.66]=1.89
C084[0.00,0.20,0.66]=0.88 5433[-0.75,0.00,0.66]=1.87
C084[0.00,0.20,0.66]=0.90 5433[-0.75,0.00,0.66]=1.88
C084[0.00,0.20,0.66]=0.90 5433[-0.75,0.00,0.66]=1.88
C084[0.00,0.20,0.66]=0.83 5433[-0.75,0.00,0.66]=1.82
C084[0.00,0.20,0.66]=0.74 5433[-0.75,0.00,0.66]=1.82
C084[0.00,0.20,0.66]=0.85 5433[-0.75,0.00,0.66]=1.85
C084[0.00,0.20,0.66]=0.77 5433[-0.75,0.00,0.66]=1.89
C084[0.00,0.20,0.66]=0.79 5433[-0.75,0.00,0.66]=1.85
C084[0.00,0.20,0.66]=0.76 5433[-0.75,0.00,0.66]=1.81
And here is a photo of the test setup on a wooden table top:
Before getting to this point, I have tested the setup with a larger network, mounted on a variety of objects (plastic and metal) and a range of distances. It appears to always have an absolute error that is possibly unique to each tag/anchor pair.