Spatial Coverage of FM Radio Transmitters in Niger State, Nigeria

In the VHF band (30 MHz-300 MHz), radio propagation is usually by space waves, which consist of direct wave and ground-reflected wave. These radio signals are affected by the electrical parameters of the ground, curvature of the earth surface, height of the antenna above earth's surface and weather conditions in the troposphere. The electric field strength of radio signals decreases with increase in distance from the transmitting antenna. In this work, measurement of electric field strength of Frequency Modulated (FM) radio signals from Crystal FM, Minna, on 91.2 MHz and Power FM, Bida, on 100.5 MHz in Niger State Nigeria, was carried out in all the 25 Local Government Areas of the state. A Digital Signal Level Meter, GE-5499, covering the signal range of 30-120 dBµV, was used to measure the signals. The longitude, latitude, altitude and also distance from the reference point (i.e., location of the transmitting antenna) were measured at every location using a handheld Global Positioning System (GPS) receiver. The parameters obtained were used to determine the coverage areas of the two FM radio signals studied in Niger State. The results obtained showed that the configuration of FM radio transmitters in Niger State does not give optimum coverage of the State.