A simplified engineering model for Earth-rotation corrections in degraded fire-control environments

The Earth’s rotation introduces systematic range and lateral deviations in artillery projectile trajectories, which become significant at medium and long firing distances. Although these effects are rigorously included in NATO-standardized firing tables and numerical ballistic models, their application is strongly dependent on digital fire-control systems, which may be unavailable in technologically degraded operational environments. This study presents a simplified analytical model for first-order Earth-rotation corrections based on time of flight, firing azimuth, trajectory angles, and geographical latitude. The analytical expressions are derived from classical equations of motion in a rotating reference frame and require only parameters commonly available in conventional firing tables. The proposed model is validated against NATO-standard artillery firing tables data from FT 155-AM-03, for representative firing ranges of 8 km, 13 km and 17 km across latitudes from 0° to 70°. The results show that the analytical corrections reproduce tabulated values with deviations not exceeding 20.3 m in range and 0.66 mil in deflection, remaining within accepted tolerance limits for artillery fire data preparation. The findings demonstrate that the simplified model should not be interpreted as a substitute for full ballistic computation or modern digital fire-control systems, but as a low-data backup correction method that can supplement older, degraded, or legacy firing-table procedures when Earth-rotation corrections are otherwise unavailable, omitted, or inaccessible.