Impact of Geomagnetic Parameter of Declination for Accurate Positioning, Navigation, and Orientation in Nigeria

Abstract

The Earth’s magnetic declination, a key parameter of the geomagnetic field, has long provided a fundamental reference for navigation, orientation, and geospatial positioning. Owing to temporal and spatial variations in the geomagnetic field, periodic model updates are essential for maintaining positional accuracy and geophysical consistency. This study modelled the spatiotemporal variability of magnetic declination across Nigeria over 15 years (2010-2025) to enhance geomagnetic referencing for sustainable navigation and mapping systems. The study employed a quantitative geoscientific methodology. The study integrated International Geomagnetic Reference Field (IGRF-14) Gauss coefficients using MATLAB programming to compute magnetic field elements and generate declination models at a 1:50,000 scale. Analytical outputs revealed significant regional variations, with the North-West, South-South, and South-East zones recording the highest declination changes of 2.40˚, 2.10˚, and 2.00˚, respectively. Conversely, the North-Central, North-East, and South-West zones exhibited relatively lower variations of 0.70˚, 1.20˚, and 1.70˚, respectively. A comparative assessment between declination values from the developed model and those derived from the global geomagnetic calculator revealed minimal discrepancies (−0.009480 to −0.001340), with root mean square errors ranging from 0.00470 to 0.00670. These findings underscore the importance of the magnitude of secular variations of magnetic declination across Nigeria. The variability of these values provides a veritable basis to support geospatial infrastructure development, accurate navigation, and calibration of inertial systems. Regular updates of isogonic maps and geomagnetic parameters are therefore recommended to strengthen national geospatial frameworks, enhance disaster preparedness, and promote SDG-aligned geoscience innovations that underpin resilient infrastructure and sustainable urban development.