CoRSEER: the calculator of rock surface exposure age and erosion rates for luminescence rock surface exposure dating

Luminescence rock surface exposure dating (LRSED) estimates the duration of rock surface exposure and the rate of erosion by analysing changes in luminescence with depth below the surface. The wider use of this method has been slowed by limitations in mathematical analysis, such as the subjective selection of the deep plateau for profile normalisation, inconsistent modelling choices across studies, and the lack of a unified inverse-modelling workflow that delivers both parameter estimates and uncertainty bounds. We introduce the Calculator of Rock Surface Exposure Age and Erosion Rates (CoRSEER), an open-source MATLAB application that standardises the full workflow from luminescence depth profiles to exposure and erosion history. CoRSEER first normalises profiles objectively using weighted three-parameter logistic sigmoidal fitting to identify the saturation level and profile shape. It then simulates profile evolution with a finite-difference forward model that includes ambient-radiation-induced signal growth, depth-dependent bleaching described by a surface bleaching rate, attenuation coefficient, and advection caused by erosion. Finally, CoRSEER performs Monte Carlo inversion to estimate calibration parameters from known-age calibration samples, apparent exposure ages for unknown samples, and steady or stepwise erosion histories while reporting the best-fit and uncertainty ranges from likelihood-based filtering. We tested all three modules by reanalysing published datasets from multiple regions, including 23 calibration samples from the original dataset. For a representative calibration profile, CoRSEER-I improved the fit (coefficient of determination of 0.928 compared with 0.868 for the literature dataset) and substantially tightened the uncertainty bounds after objective renormalisation. Across the compiled studies, the CoRSEER-derived apparent ages cluster close to the one-to-one line relative to the published values and span approximately 1 year to 8.5 thousand years, while erosion estimates for a benchmark case remain comparable to the literature results. These results show that objective normalisation plus a transparent, standardised inversion framework can materially improve the reproducibility of luminescence rock surface exposure dating and support consistent inter-study comparisons of exposure and erosion history.