This research work focuses on attaining optimal parameter settings for precise identification of seismic signals at the output of large ring laser gyro through the application of the STA/LTA trigger algorithm. Lately, the sensitivity of rotations has been improved by at least 5 orders of magnitude because of significant upscaling of very large perimeter ring laser gyroscopes. This process in rotational sensors technology brought about the successful detection of rotational signals resulting from earthquakes several thousand of kilometers away. The identification of seismic signals at the output of the large ring laser Gyro may be carried out using the trigger algorithm. As soon as an assumed seismic event is detected, recording and storing of all incoming signals begins. It stops after trigger algorithm 'declares' the end of the seismic signal. The ‘short-time-average through long-time-average trigger' (STA/LTA) is the most widely used algorithm in weak-motion seismology. It constantly calculates the average values of the absolute amplitude of a seismic signal in consecutive moving- time windows. All records, along with those falsely triggered, must be inspected. The completeness of the event records is checked (seismic noise, the P arrivals, the coda waves), and the causes of the false triggers are analyzed. After the evaluation is completed, the parameters are modified consistent with its findings and the new settings archived for documentation purposes. By repeating this process one will progressively discover the satisfactory parameter setting.
With high demand in performances, ring laser is proposed as an angular measuring transducer, due to its many considerable advantages compared to other means of angle’s measurement, since it’s based on the physical fundamentals, methods, equation/logarithms are developed and experimental work using high precision goniometer, this paper focus on reducing the instability, zero shift, the resolving power to as low as 0.05, the technique required to determine the output frequency within angle of periods in the RL output signals in an entire rotation (2π), The output characteristics instability of scale factor (K1) and zero shift (Ko ) was observed with time and the effect of instability on the rotational velocity of RL in regard to component error in measurement was minimized, the type of RL used proved to be the square type as different values based on CW and CCW was recorded.
It became necessary for proposing a remote non–contact method to measure angular positions and movement of an objects using Laser Dynamic Goniometer (LDG) as compared with the usual Photo-electrical autocollimators with narrow range of about 1deg. This article present analysis, errors as well as experimental results of using Laser Dynamic Goniometer to measure wide range with accuracy of approximately 0.1 arcs and a possibility of measuring constant angles with accuracy of 0.005 …0.1 arcs in the range of possible angles of 15…30degrees.
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