Abstrakt
The research focused on electromagnetic phenomena related with earthquakes is a very rapidly expanding field. The main purpose is to find a possible short time earthquake prediction.
In the past, various measurements in a wide frequency spectrum from DC to VHF have been done, but most of them have covered only small areas. The DEMETER satellite was the first tool designed for doing observations on a global scale.
In this paper, we present pre-processing of the ULF waveform observations as a first step in the analysis of the possible earthquakes precursors. In the first part we describe the ICE ULF instrument on board DEMETER.
In the next part we present a method to pre-process the ULF waveform. This includes description of the time intervals where data are corrupted and subtraction of the electric field induced by the satellite motion in the geomagnetic field.
In the last part we show an example of the ULF waveform perturbation prior to the strong earthquake.