Hi,
I would like to know what unit of measurement is used in the trigger threshold? Do you know what intensity 3.95 can and cannot withstand?
Thank you
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Hello waw, and welcome back to the community!
I assume you are referring to the threshold value in RSUDP (for other readers, explained here).
The trigger threshold value (like 3.95) used in the alert system is actually a ratio, not a direct unit like velocity or acceleration. Specifically, it comes from the STA/LTA algorithm, which compares short-term signal energy to long-term background noise (there is an excellent explanation in this document). So, in this example case, when that ratio goes above 3.95, the system treats it as a potential event and sends out an alert.
As for what intensity, that depends on many different factors (installation position, location, type of material upon which the Shake is positioned, soil type and density, depth to bedrock, structural footing and attachment to bedrock, bedrock type, and more). So, the best way to understand what that value means for your specific installation is to test it to find the best STA/LTA values for what you want to detect/record as events.