Mobile AR tele-preservation of architectural heritage under spatial mismatch

Restricted access to architectural heritage limits expert observation, documentation, and preservation planning. This study examines how mobile augmented reality (AR) can support stable, structured observation when the deployment space differs from the heritage site. Because one-to-one physical–virtual correspondence and global registration rarely hold, we prioritized cognitive coherence over geometric accuracy. We present a decoupled multi-anchor mapping strategy that locks yaw via device sensors and applies translation-only QR-anchor corrections to reduce rotational leverage. In a Seokguram Grotto deployment inside an ETRI building, the overlay stayed perceptually stable across viewing distances, with 0.19 mm position jitter against the 6-DoF baseline’s 0.32 mm. A user study with 32 experts showed a strong association between perceived AR-specific experience and perceived educational effectiveness, with Spearman’s ρ = 0.86. This correlational association does not establish a causal educational effect. Perceptual stability and cognitive coherence emerge as design considerations for remote observation of restricted-access heritage.