Fig. 3
From: Acoustic positioning in a reflective environment: going beyond point-by-point algorithms
3D-timeseries of the daily average VPS position of fixed transmitters: synchronisation transmitters (green) and reference transmitters (red). The study area is outlined in the x–y plane. The calculated positions are in the z-direction. Perfect positions would result in a straight vertical line; any deviations from the vertical line indicate positioning errors