Japan Earthquake Early Warning EEW2019 rebuild
Since the loss of twitter/EEWBOT around August, 2018, J1/REC has not been able to provide real time Japan Earthquake Early Warning (EEW) and over-the-air emergency alerting.
REC has obtained a new source for EEW data and we are once again providing EEW data. A new watchdog program has been built that monitors a RESTful interface once every 2 seconds for new EEW messages.
Alerts that involve an earthquake episode where the intensity on the Japanese Shindo scale (of 0 to 7) reaches either 3 or 4, the system will send an RML command to Rivendell that will generate a short tone over all three J1 channels to advise of the warning.
Data from all EEW messages received for that alert will be cached and upon receipt of the final EEW message, the watchdog will send notifications to the main database about each message received in order to update the EEW Log. A message is also sent to Twitter (on @J1_Quake).
A separate program on the main server checks the database every 20 seconds for new EEW log entries. When it encounters new entries, it will construct a new advisory message based on the parameters of the earthquake received in the EEW Log. The audio file is then uploaded to the Rivendell server.
Alerts that involve an earthquake episode where the intensity is Shindo "5 lower" or greater will result in RML commands being sent to Rivendell to load a cart that is appropriate to the geographic area of Japan where the earthquake is located (there are 8 different areas based on geographic coordinates of the epicenter), then an RML command is sent on all three channels to advance to that cart. The watchdog program will wait for 30 seconds and will then perform an rdimport on the audio file that was described in the previous paragraph. Once the import is complete, the watchdog will send an RML command to queue that cart as the next item and it will play after the initial alert message plays.
Updates made to the REC/J1 Japan Earthquake public site (eew.j1fm.tokyo) to support the new EEW logs while maintaining backward compatability with log data from EEWBOT.