Active acoustic source‐receiver pairs are employed to monitor the tip movement of a propagating hydraulic fracture. A series of experiments has been conducted with an acoustic system that has transducers mounted in the loading plates of a tri‐axial cell situated in the Geotechnology Department, TUDelft. The hydraulic fractures are created by fluid injection via a borehole. The tests in this study feature both pre‐existing and hydraulic fractures and aim to characterize the interaction between them. From the fracture imaging point of view, the tests also evaluate the robustness of the monitoring performance under the interaction. Here we focus on the data processing that is adapted to these special tests and comparison between the results for the monitored fracture and the fracture recovered from the post‐mortem analysis.