Emergency Warning Services via GNSS Signals

Galileo is a Global Navigation Satellite System developed by the EU (European Union), covering the whole world. The system is organized by 26 satellites now. It will be 30 in 2020. In addition, QZSS (Quasi-Zenith Satellite System) was produced by Japan. This system's positioning service covers not only Japan, but also South East Asia and Oceania. The main purpose of both systems is positioning service. Besides that, both sides, EU and Japan, have been planning “double-use strategy” of their satellite systems. More precisely, positioning service is for ordinary time as well as danger notification and subsequent instruction to escape from disaster situations - hence the term “double-use strategy.” For instance, ISRO (Indian Space Research Organization) has decided to use our idea and to employ our emergency messages for their satellite. The EWS (Emergency Warning Service) was named by EU, while the DC report (Report for Disaster and Crisis Management) was named by Japan. We decided to name “common EWS” for both services, during our project. In this paper, we report an interim result of our joint project being the development of a common EWS message. The amount of information that can be relayed/transmitted via GNSS satellites is very small. We had to express all necessary disaster information in 122 bits. In other words, we have designed an information structure of Emergency Warning that can evolve to international standards in 122 bits. This message can be employed on small satellites. On the other hand, the limitation of 122 bits was according to constraint of Galileo system. Galileo uses 122 bits for broadcast on E1 and E5B band (I/NAV). QZSS has 65 additional bits that are available in L1S band (MT44). Therefore, we will start to design for Asian Unique message (Figure 1). We have been building some application system on QZSS and Galileo using the common EWS message to execute field test. Japan recently experienced The Great East Japan Earthquake and giant Tsunami in 2011. Our broad band communication network was totally destructed in critical damaged area. We would like to make a big contribution by using satellites as the main communication network during the next disaster.