Quality of AM Radio Reception at Night and Daytime for Future Use in Natural Disaster Situations

Brazil has more than 10,500 radio stations, which broadcast live sports, music, services and entertainment. It is estimated that 86% of the Brazilian population listens to radio programming, making it, therefore, a more adaptable communication vehicle for use in different media and situations, such as the possibility of using it to transmit alerts and warnings in situations of natural disasters. The objective was to compare the propagation of AM radio transmissions at night and during the day with commercial receivers, also, to prove, with a simple methodology and at a reduced cost, problems and advantages that may occur in transmissions on the aforementioned frequencies, instigating research scientific research with students from an elementary school in Brazil. The receptions were carried out by the students during the day (9:00 and 12:00) and at night (7:00 and 00:00) using two receivers, one powered by batteries and the other by a battery (car receiver) and recorded for later group analysis adopting the SINPO code methodology. The results showed that several commercial AM radio stations were received at night, but during the day it was not possible to receive reception at any of the times analyzed. During the night, many distant stations could be captured, which negatively influenced the reception of the stations studied, but could be used to explain the propagation of the electromagnetic wave, the presence and performance of the Ionosphere and its characteristics. Due to the propagation behavior of the electromagnetic wave of AM radio stations, which has some peculiarities when compared to commercial FM stations, the use of this band in the region under study, in the case of alerts and warnings of natural disasters, must be better analyzed to ensure satisfactory results are obtained.