SeRAVi: A Spatio-Temporal Data Distribution Visualization System for Mobile Sensor Data Retrieval

With the development of sensor technologies in recent years, mobile sensor devices such as smartphones have become widely used. Thus, there has been much attention to study on utilizing mobile sensor data generated by these devices. Here, the distribution of such kind of data tends to be spatially and temporally ununiform. Therefore, in order to assists users to retrieve such an ´ununiformly distributed´ data, it is needed to provide a system that helps users to grasp spatio-temporal distribution of sensor data. In this paper, we propose and implement a novel system that visualizes spatio-temporal distribution of sensor data in order to make it easier to retrieve mobile sensor data. Our system divides a map interface into grids and overlays a 2-dimensional histogram which shows the spatial distribution of the number of sensor data. The system also provides the temporal distribution of sensor data which are currently shown in the map interface. These functions enable users to grasp spatio-temporal distribution of sensor data and makes it easier to retrieve sensor data.