What are the x-axis units on the RaspberryShake helicorder? In Swarm it shows “counts” but what does that mean? How do I get to displacement or other units? I have a 1D unit.
Dick
Hi Dick,
Counts are a measure of the voltage measured on the geophone circuit. In order to convert them to a human-readable format, they need to be mathematically “deconvolved” from the geophone’s frequency response, which is essentially its resonance at various frequencies. Several programs can do this, including Swarm and obspy, among many others.
This deconvolution is called “Using Calibrations” in Swarm. If you are forwarding your Shake data to our server, the server will generate a file that contains the math behind your geophone’s frequency response. Swarm has the ability to download and apply this file in order to show human-readable units. The way to do this is:
- Make sure Data Forwarding is on, from your Shake’s config page (the gear icon
) - Connect to the Raspberry Shake community data server at
caps.raspberryshakedata.com, port16022 - Scroll through the stations, or start to type your station name (most likely “R-x-x-x-x”) to jump to your station, and double click on it
- Go to the Wave View Settings (
) - Check the box labeled “Use Calibrations”
- Your data should now appear in meters per second
I also sent you a direct message with a paper that helps explain what counts are and where they come from, just so you know. Hope this helps.
Ian, thanks for the information. I have been using Swarm (ver 2.8.8) and have it set for the calibration on mode. However, it still shows as Counts in the wave display. Any suggestions? And thanks for the SRL paper.
Dick
Hi Dick,
Can you send a screen shot of your Swarm window?
Ian