Peer-reviewed articles 17,970 +



Title: SIGMA-DELTA PHASE LOCKING LOOP FOR GEOPHYSICAL RESEARCH

SIGMA-DELTA PHASE LOCKING LOOP FOR GEOPHYSICAL RESEARCH
V. Zhmud;Y. Fomin;L. Dimitrov;S. Panov; V.Semibalamut
1314-2704
English
20
2.1
Continuous measurements of deformations of the Earth's crust make it possible to
record changes in their character in several characteristic parameters. Such parameters
include the amplitude, phase, and frequency of periodic oscillations, for each
characteristic frequency separately, as well as random typical or atypical artifacts. All
this information with proper processing can be used for various purposes, one of the
most important tasks in this case is to reliably identify earthquake precursors. These
studies require a preliminary long and detailed record of all measurements, followed by
mathematical and statistical processing. In this case, strain measurements are carried out
using laser meters that convert the ultra-small increment of the distance between the
control points into digital samples. These increments of the distance in the measuring
system are initially converted to phase increments of the high-frequency laser radiation,
then to the same phase increments of the electrical signal at an intermediate high
frequency, then the phase increments are measured using a special device called a phase
meter, which generates digital samples of the phase increments proportional to the
increments of distances. Phase meters have rather high requirements for the accuracy
and speed of measurements; in addition, they must be protected from the influence of
deep amplitude modulation on the accuracy of measurements. In any case, these
modulations should not be fatal for continuous phase measurement, that is, there should
be no loss of measurements during a sharp decrease in the signal amplitude. This paper
proposes a new method for continuous high-precision measurement of phase increments
using a phase-locked loop (PLL), organized by a fundamentally new principle of
operation, namely: similar to the operation of a sigma-delta analog to digital converter
(ADC). This type of ADCs uses auto-tuning of the output signal to the input in a circuit
containing only an integrator and a comparator, as a result of which high-frequency
transients in the form of fast self-oscillations near the equilibrium state constantly occur
in this loop. The advantage of this method allows measuring of the low-frequency
component of the input signal with extremely high accuracy.
conference
20th International Multidisciplinary Scientific GeoConference SGEM 2020
20th International Multidisciplinary Scientific GeoConference SGEM 2020, 18 - 24 August, 2020
Proceedings Paper
STEF92 Technology
International Multidisciplinary Scientific GeoConference-SGEM
SWS Scholarly Society; Acad Sci Czech Republ; Latvian Acad Sci; Polish Acad Sci; Russian Acad Sci; Serbian Acad Sci & Arts; Natl Acad Sci Ukraine; Natl Acad Sci Armenia; Sci Council Japan; European Acad Sci, Arts & Letters; Acad Fine Arts Zagreb Croatia; C
559-566
18 - 24 August, 2020
website
cdrom
7033
earthquake precursors; crustal deformations; geoinformatics; monitoring;
phase measurements; phase locked loop; sigma-delta ADC