Implementation of haversine formula for counting event visitor in the radius based on Android application

Location based services (LBS) is one of the new technologies to gain a position in the geographic presence of mobile devices. The presence of LBS technology can be used for information mapping of an area such as the existence of the event. The existence of event is influenced by the number of visitor to the event, because it can be attract people to attend the event. Haversine formula is the method used to calculate the distance from two different points. In this study, Haversine formula applied for calculating distance between the user with a set of events that exist. To determine the presence of visitors is done by calculating the results of haversine formula with a radius area of each of these events. From the calculations, if the users are in the radius area, the number of visitors the event will be calculated and updated. In this research, we implemented this method in android application. Therefore, haversine formula can be used for the calculation of the distance and can be implemented to determine the number of visitors who signed into events.