Optimizing Campus Radio Wave Reach and Field-Signal Study of Search FM 92.3 MHz in Minna, Nigeria

Abstract

Geographic information systems (GIS) and viewshed analysis are powerful tools for communication-network planning, particularly for modeling radio-wave propagation and optimizing transceiver locations. This study integrates GIS-based viewshed modeling with field-measured electric-field strength to assess and improve Search FM 92.3 MHz broadcast coverage at the Federal University of Technology, Minna (FUT-Minna), Niger State, Nigeria. A geo-referenced digital map of Minna Metropolis was processed in AutoCAD Land Development and imported into ArcGIS 10.1. Field measurements electric-field strength (30–120 dBµV) using a GE-5499 Digital Signal Level Meter, plus GPS-derived coordinates and altitude were collected along five drive routes (A–E), alongside line-of-sight (LOS) distances. A digital elevation model (DEM) from ASTER imagery, integrated with satellite data, enabled viewshed analysis for the existing 52 m mast and a proposed 80 m site. Statistical analyses (linear regression, Pearson correlation, one-way ANOVA) examined signal strength relationships with distance and terrain. Results indicate only 23% of the 39,100-ha study area achieves primary (Grade A) coverage, with 51% secondary and 26% fringe. Regression showed a strong negative LOS distance-signal association (r = –.78, p < .001); ANOVA revealed route variations, F (4, 95) = 12.30, p < .001. Viewshed modeling suggests relocating to higher terrain could boost Grade A coverage to 45% (+22 percentage points). Terrain obstacles like Maitumbi Hills, buildings, and vegetation cause nonline-of-sight zones and multipath loss. This pioneering GIS-field integration for Minna FM coverage offers a practical framework for antenna optimization and mast siting