Seismometer correction

Signals filtration program

The program Signals filtration has a function of seismometer frequency characteristics correction by means of the reversed filter used for decreasing the sensor low-frequency limit.

In terms of mathematics, the frequency correction process is described as follows:

F0 ⋅ Fk = F1,

where F0 – frequency characteristics of the sensor prior to correction;
Fk – frequency characteristics of the correcting circuit;
F1 – sensor frequency characteristics upon correction process completion.

The program Signals filtration has a reversed filter that allows to reduce the sensor low-frequency limit in 10-20 times. The only drawback of this filtration is the increase of seismometer’s natural oscillations. The interdependence of such parameters as seismometer’s natural oscillations, damping ratio, and inertial mass has been found by American seismologists Keiiti Aki and Paul G. Richards and described in the book “Quantitative seismology: theory and methods”. The natural oscillations of the seismometer are directly proportional to the damping ratio and negatively related to the inertial mass of the seismometer.

Фильтрация сигналов. Коррекция сейсмометра
“Signals filtration” program: reversed filter configuration window