In perpendicular recording, substantial erasure of the stored data patterns can occur during the writing process. Among all those erasure processes, sidetrack erasure (STE) is one of the critical issues in drive head/media integration. Unlike the adjacent track erasure (ATE) process, the locations of the STE affected areas are often many tens of tracks away from the central writing track location. In this work, we report on an experimental investigation and quantification of the general attributes and the origins of the STE processes in various situations. Particularly, we thoroughly characterize some distinctive signatures and behaviors of STE processes by employing both the amplitude- and BER-based STE measurement methods in combination with a novel magnetic force microscope characterization technique.