The exponential growth of the size of seismic data recorded in seismic surveys and real time data monitoring makes seismic data compression strongly demanded. Furthermore, compression will lead to an efficient use of the bandwidth assigned for the communication link between the seismic stations and the main center. In this paper, two convolutional autoencoders (CAEs) are proposed for seismic data compression. The two algorithms are mainly based on the convolutional neural network (CNN), which has the capability to compress the seismic data into feature representations, thereby allowing the decoder to perfectly reconstruct the input seismic data. The results show that the first model is efficient at low compression ratios (CRs), while the second model improves the signal-to-noise ratio (SNR) from about 3 dB to 12 dB compared to the other benchmark algorithms at moderate and high CRs.
1 January 2024 in Journal of Advanced Engineering Trends
One of the main devices in the earthquake monitoring system is the digitizer, which converts the analog signal to a digital one. We design and implement a trigger digitizer to store/transmit the seismic data. The implemented digitizer consists of several blocks, i.e., the power source, the front end circuit, analog to digital converter (ADC), GPS receiver, microcontrollers, microprocessor, and deep learning picking module. Besides, we use three finite impulse response (FIR) filters to decimate the sampling rate of the input seismic data. In addition, we utilize the CapsPhase network to pick the first arrival time of the earthquake. In this way, the digitizer is a trigger device, where an enable signal is released once the earthquake is detected to take the appropriate action. The CapsPhase is evaluated using the seismic data recorded by the Egyptian National Seismic Network (ENSN), NRIAG. The CapsPhase shows a robust picking performance compared to the benchmark methods.
A digitizer is considered one of the fundamental components of an earthquake monitoring system. In this paper, we design and implement a high accuracy seismic digitizer. The implemented digitizer consists of several blocks, i.e., the analog-to-digital converter (ADC), GPS receiver, and microprocessor. Three finite impulse response (FIR) filters are used to decimate the sampling rate of the input seismic data according to user needs. A graphical user interface (GUI) has been designed for enabling the user to monitor the seismic waveform in real time, and process and adjust the parameters of the acquisition unit. The system casing is designed to resist harsh conditions of the environment. The prototype can represent the three component sensors data in the standard MiniSEED format. The digitizer stream seismic data from the remote station to the main center is based on TCP/IP connection. This protocol ensures data transmission without any losses as long as the data still exist in the ring buffer. The prototype was calibrated by real field testing. The prototype digitizer is integrated with the Egyptian National Seismic Network (ENSN), where a commercial instrument is already installed. Case studies shows that, for the same event, the prototype station improves the solution of the ENSN by giving accurate timing and seismic event parameters. Field test results shows that the event arrival time and the amplitude are approximately the same between the prototype digitizer and the calibrated digitizer. Furthermore, the frequency contents are similar between the two digitizers. Therefore, the prototype digitizer captures the main seismic parameters accurately, irrespective of noise existence.