Nankai trough earthquake text information for QZS's disaster and crisis management report test delivery

Quasi-Zenith Satellite, QZS or Michibiki, distributes the disaster and crisis management report (DCR) on the L1S radio channel.

A new field, Information Serial Code, has been added to the transmission format of “Nankai Trough Earthquake” in the update of the 10th edition of the interface specification. In addition, DCR test distribution has been done once a month until now, but in March 2022, it will be done twice on the 10th and 28th.

Text information related to the Nankai Trough Earthquake is transmitted 6 UTF-8 Japanese characters per message, and up to 378 characters can be transmitted by concatenating multiple messages. DCR transmits one message every 4 seconds at the shortest, and another DCR message may be inserted in the middle of the multiple messages. In addition, since the text information of the Nankai Trough earthquake is transmitted in no particular order, it is not possible for the receiver to present the information sequentially, and the receiver requires sorting the messages. After all, transmitting textual information of 378 characters needs the receiver at least 4 minutes and 12 seconds to decode the information. In the test distribution so far, the number of characters is very large and it was truncated in the middle of the information text. When a message is missing due to fading at the DCR mobile receiver, it is required to present them with hidden characters or to keep waiting for receiving the missing message.

The text information of the Nankai Trough Earthquake in this DCR test distribution is simple and easy to understand.

(the Japanese text)

南海トラフ沿いのプレート境界で通常とは異なるゆっくりすべりが発生していることが推定されます。この通常とは異なるゆっくりすべりの発生により、南海トラフ地震の想定震源域では、大規模地震の発生可能性が平常時に比べて相対的に高まっていると考えられます。今後の政府や自治体などからの呼びかけ等に応じた防災対応をとってください。

(the English translation)

It is estimated that an unusual slow slip occurs at the plate boundary along the Nankai Trough. Due to the occurrence of this unusual slow slip, it is considered that the possibility of large-scale earthquakes is relatively higher in the hypocenter area of the Nankai Trough Earthquake than in normal times. Please take disaster prevention actions in response to further information from the government and the autonomous body.

This text information consists of 158 Japanese characters, so the receiver can present this text in 1 minute and 48 seconds. This isn’t mentioned in the official information, but I think it’s a big improvement. It’s also nice to have a summary with the Information Serial Code.

I am looking forward to the test delivery this month as well.

Related article(s):

• Test data for Michibiki's enhanced disaster and crisis management reporting service 26^th May 2024
• Update of QZS L1S signal specifications（IS-QZSS-L1S-006） 30^th October 2023
• Test broadcast of the disaster and crisis management report from quasi-zenith satellites and it's revised specification 28^th January 2022
• Reception of disaster and crisis management report sent from QZS-1R on u-blox ZED-F9P 27^th December 2021
• Test data delivery of disaster and crisis management report from QZS-1R 11^st December 2021
• Documents on test delivery for QZSS's disaster and crisis management report 9^th December 2021
• Arbitrary format transmission of QZSS's disaster and crisis management report 28^th March 2021
• Test message delivery of disaster and crisis management report sent from QZSS 25^th March 2021
• QZSS's Disaster and Crises Management Report signal reception with Spresense, a Sony's board microcomputer 23^rd November 2019