Fault localization in planetary gearboxes based on vibration signals poses certain challenges due to the complex internal structure and signal transmission paths. In our previous work, we proposed a method utilizing a On-Rotor Sensing (ORS) sensor for fault localization, in which the tidal period effect was leveraged to derive characteristic encodings corresponding to the number of single-tooth meshings (NSTM) lagging behind the absolute phase reference (APR) for different fault tooth. Building upon these encodings, this study introduces two quantitative indicators Mean Encoding Value (MEV) and Mean Spearman Coefficient (MSC) to accurately identify the faulty tooth position on the sun gear. MSC is employed to evaluate the correlation between the characteristic encoding and the experimental meshing sequence, while MEV is used to further distinguish the most relevant encoding set through statistical analysis of the mean value distribution. The effectiveness and reliability of the proposed approach are demonstrated through two sets of experimental validations under different working conditions.