I am using an indoor positioning system based on UWB beacons. This system is composed of four UWB MDEK1001 anchors placed in the four corners of a room with a size of 10m x 5m. The system appears to work properly, the distances to the various beacons are logged correctly, the position is accurate and the drone hovers maintaining the position precisely.
The problem is that approximately one minute after startup the EKF3 position jumps, gaining an offset of several meters, after which it stabilizes again. This makes it impossible to use waypoints consistently between flights since, although the relative accuracy of the system remains good this offset applies an absolute and random error in the position preventing the use of autonomous missions.
Below, I am going to plot the positions of the EKF3 in conjunction with the position reported by the UWB system. At 19 seconds the EKF3 initializes and its position jumps to the position reported by the UWB system (4m in X, -2m in Y). But at 49 seconds the position suddenly jumps in a random direction gaining a large offset before stabilizing again.
This behavior is consistently repeated in all the tests I have performed with this position jump always occurring at 49s as explained above.
I attach two logs in which this behavior can be observed in the beginning of the log.
LOGs: Logs UWB - Google Drive
If someone with a deeper knowledge on the subject could advise me on why this phenomenon occurs or how to solve it, I would appreciate it.