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The Histogram Folder
The top level folder named "histogram" contains daily CSV files where an entry is written to
file each minute, recording peak data values and other parameters. The files are simply
named by date (e.g. 2016-12-31.csv) and can be opened using Waves. Open the file using
Excel or a text viewer and you will be able to plot the minute-resolution data:
•
An estimate of the peak motion the 3D sensor in the last minute (raw and units)
•
The absolute peak values for the 1D channel in the last minute (4-ch models only)
•
Input Voltage and CPU Temperature at the time of the data entry
•
Latitude, Longitude, Altitude, and other GPS parameters at the time of data entry
•
The clock stability (vcxo) value, and the percentage of storage memory available
The file header contains information about the station, including parameters for converting
raw values into sensor units.
Divide the raw value by the cpv,
290183 ÷
838860.8
an estimate the 3D sensitivity is an average of the individual channel sensitivities. The peak
vector sum (both 3D and 2D) can be calculated accurately using Waves analysis software.
MiniSEED files
Continuous data files in the Gecko are in MiniSEED format, which is a widely adopted
international standard format for seismic data. You can find out more about this data format
at the IRIS website:
http://ds.iris.edu/ds/nodes/dmc/data/formats/miniseed/
Being a "data only" format, the lack of embedded station information makes it impossible to
simply open a file and read a ground motion value (and therefore calculate magnitude). The
way we have handled this is to embed a seismograph settings (.ss) file in every Hour folder.
If you use our Waves application to open a data file, it will look for an .ss file in the file's
folder and automatically read and apply the appropriate corrections to the data so that
ground motion units are displayed. Similarly if you drag an entire Hour or Day folder into
Waves, it will read the first .ss file and apply these station settings to the merged data file
displayed in the Waves window.
The problem then becomes needing to keep the .ss files and MiniSEED data files together to
retain this association. The simplest solution is to use the "Save As..." function in Waves to
save the file in "PC-SUDS" format (a less common international standard seismic data
format) which embeds all of the relevant station data within the data file. Alternatively,
select the option to save the file as a "MiniSEED zip" file which will bundle the .ms data with
the .ss info file (and a station.xml file) into a zip file that can be read directly by Waves.
sens
and
÷
750.0
÷
2
= 0.00023062
gain
to estimate the value in units, e.g:
m/s
(or 0.23062 mm/s). This is only
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