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Satoshi Takahashi

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Test broadcast of the disaster and crisis management report from quasi-zenith satellites and it's revised specification

category: gnss
tags: dcr qzss

Test broadcast of the disaster and crisis management report

The quasi-zenith satellite Michibiki broadcasts not only positioning signals but also domestic disaster alert signals. This disaster and crisis management report (DCR) is available to anyone for free. DCR reception can also be done with the microcomputer Spresense, which can be purchased for about 50 USD, so we can feel free to try it.

Since we do not know when a disaster will occur, a test message assuming a serious disaster is broadcast once a month. Previous test broadcast contained 11 scenarios over a two-hour period.

However, in the test broadcast on January 27, 2022, the broadcast time was shortened to 1 hour and 35 minutes. The scenario related to “Nankai Trough Earthquake” has been deleted, and the number of scenarios has been reduced to 10.

The interface specification

On the other hand, on January 24, 2022, the DCR interface specifications were updated to the 10th edition (IS-QZSS-DCR10).

Some of the messages regarding the Nankai Trough earthquake mentioned above have also changed. Information Serial Code is added to the message and is shown each of:

  • “Under investigation A” (holding an evaluation review meeting),
  • “Under investigation B” (significant changes in the strain gauge are observed, and an extraordinary evaluation study meeting will be held),
  • “Under investigation C” (change in plate boundary fixation state is observed, extraordinary evaluation study meeting will be held),
  • “Giant earthquake alert”,
  • “Caution for a huge earthquake”,
  • “End of investigation”, and
  • “others”

Since the DCR message is created based on the XML file received from the Japan Meteorological Agency, it is presumed that this update was made by the Japan Meteorological Agency.

Overall, there were no major changes. In response to the Nankai Trough earthquake notification, there is no change in the fact that it is a free-form transmission rather than a disaster code transmission, which is a little unsatisfactory for me.

However, I am very grateful for this mechanism, which allows us to obtain disaster information from all over Japan without monthly payment with a small receiver.

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