Data Format

Upgraded induction coil stations with 24-bit AD-converter, timign with GPS 10MHz reference signal are labeled with (250). The data is sampled by 250Hz and stored to hourly binary files. The upgraded system use same induction coils used at SGO stations since 2002/2003 onwards. All the stations will be upgraded. KIL has been running prototype of 250Hz since Sep 2015. SOD 250Hz is running parallel to old system.

The stations IVA,SOD,ROV,OUL and NUR have identical instrumentation since 2003 (KIL until 19.11.2015). Small differences between gain of the amplifier exists. Data samples taken with 40Hz sampling, are stored with GPS timing and final raw data is stored into MATLAB format version 4 (.MAT). All three components are stored to different hourly files. Hourly file includes 144000 data points. Data storing system writes also GPS status to the log file. Data storing system uses 16-bit AD-converters. The voltage values from -10V to 10V is converted to bit counts (-32768 -> +32768).