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What you see is normal and is an artifact of how Swissranger TOF camera operates. There are a few variants of SR4000 cameras rated for maximum distance of 5 and 10 meters, this range is called a "non-ambiguity range". Measurements are subject to a so called “ambiguity” or a “back-folding” phenomenon that is due to the periodicity of the signal that is used for the distance measurement. If there's an object outside of that range the distance measurement id ambiguous: it could be at x, or x+D, x+2D, etc. For example, for a 5m camera if an object is 7 m away, it will show up at 7-5=2m. See Section 8.3 in SR4000 manual for full explanation.

As Ivan said it is possible to filter those distance values based on confidence values as they will be pretty low.

Also, there's a few papers that attempt to deal with that problem:

Probabilistic Phase Unwrapping for Time-of-Flight Cameras

Multi-Frequency Phase Unwrapping for Time-Of-Flight Cameras