Abstract
The true or full ground motion information is frequently necessary in seismology to deal with a wide range of urgent scientific and applied problems; this information includes knowledge not only of ground motion along three axes at the recording site, but also the values of tilt or rotations of the surface at the site. This problem is usually attacked using a special type of seismic instrument-tiltmeters. Gyrotiltmeter is one of the many types of tiltmeters in which the gyroscope is used as the active sensor. The main obstacle in the way of developing effective long period seismic instruments, including gyrotiltmeters, consists in various sorts of noise, frequently not of seismic origin, which influence on the instrument increases as its frequency characteristic is extended toward longer periods. The present paper is concerned with problems arising in the use of optimal filters to detect seismic signals in records of a gyrotiltmeter where also noise may be present, e.g., that due to air pressure fluctuations. Examples are provided of tests of the algorithms, which clearly demonstrate that the application of the optimal filters to records of long period gyrotiltmeter channels can significantly enhance the signal/noise ratio to detect seismic signals disguised by induced noise.
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Original Russian Text © V.V. Gravirov, 2009, published in Seismicheskie Pribory, 2009, No. 1, pp. 23–33.
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Gravirov, V.V. Optimal filters application for allocation of seismic signals in long period channel of the gyrotiltmeter. Seism. Instr. 46, 13–20 (2010). https://doi.org/10.3103/S0747923910010020
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DOI: https://doi.org/10.3103/S0747923910010020