Boundary Inference Module for Magnetopause Detection from Local In-Situ Measurements

This methods-focused deposit presents a complete, reproducible module for detecting magnetopause crossings using only local in-situ measurements of magnetic field and plasma properties. Unlike traditional models relying on spacecraft ephemeris or empirical surface fits (e.g., Shue97), this approach enables regime inference (magnetosphere vs. magnetosheath) from measured time series alone, using a transparent logistic regression framework over a minimal feature set. Key contributions include:A curated THEMIS crossing dataset (2007–2016; ~29k events) as ground truthA mission-agnostic classifier trained on local B-field, density, velocity, temperature, and derived turbulence/pressure featuresFull stress-test suite: jitter, dropout, cadence degradation, ablationDay/flank/night stratification of results for spatial generalization testingComparative benchmarks vs. Shue97 model crossings (precision, recall, offset)False-positive screening against other known boundaries (bow shock, PSBL, tail current sheet)A structured analysis of ambiguous crossings (p(MSH) ~ 0.5) as a potential proxy for boundary oscillation and instabilities (e.g., FTEs, K–H vortices) Optional encoding into a discrete regime ladder (k-ladder) is evaluated under flicker, ambiguity, and monotonicity metrics, with retention only if performance is improved. The system supports both retrospective and low-latency operation modes, and all pipeline stages are specified using NASA CDAWeb HAPI endpoints to ensure full reproducibility. This work introduces no new physics, but offers a rigorously validated and operationally useful boundary inference discipline for cross-mission deployment and time-local boundary detection. Copeland Resonant Harmonic Formalism (CRHC v1.0) License: Copeland Resonant Harmonic Formalism (CRHC v1.0) This work is licensed under the Copeland Resonant Harmonic Copyright (CRHC v1.0). Attribution is required for all uses. Collaboration, academic discussion, and non-commercial use are permitted. Commercial use, resale, or incorporation into proprietary systems is not permitted without explicit written permission from the author. Derivative works must preserve attribution and must not remove or alter the stated license terms.