Visit Geobit @ 2020 SSA Annual Meeting

Visit Geobit @ 2020 SSA Annual Meeting

GEObit and ISTI are exhibiting at 2020 SSA Annual Meeting, 27–30 April, Albuquerque, New Mexico.

GEObit provides high sensitivity wide-band and near broad-band seismic sensors, surface or borehole type, and high dynamic range, low power 32bit ADC data loggers with local data storage and real-time telemetry over seedlink protocol. We are focusing on low power and cost-efficient solutions so we provide to our customer seismic networks with low installation and maintenance costs. Our instruments are ideal for local and regional seismicity and micro-seismicity monitoring and for seismic events such as those induced by unconventional hydrocarbon extraction. Our high fidelity data loggers ensure that these signals are recorded with the highest resolution and timing accuracy.

Together with ISTI, our USA & Canada representative, we welcome you to visit us at our booth, #12, to meet our team and learn about our new upcoming instruments and technologies. We will also be available to answer your questions.

More information about 2020 SSA Annual Meeting may be found here.

Wideband versus Broadband Seismic Sensors in Local and Regional Seismicity Monitoring

Wideband versus Broadband Seismic Sensors in Local and Regional Seismicity Monitoring

This poster was presented by N. Germenis at AGU Fall Meeting 2019, San Francisco, CA.

Abstract

As local earthquakes don’t produce very low frequencies, the use of expensive broadband seismometers, for local and regional seismicity monitoring, may be avoided. Low frequency geophones have been used in the past for this type of monitoring, however their response is typically very limited below 2Hz, and thus a magnitude overestimation may occur. In most cases, wide band seismic sensors are typically used in local and regional seismicity monitoring experiments, but it is not always clear what are the achievable measurement quality levels and how they compare to solutions that are more expensive.

This work tries to shed light into this problem, by presenting a comparative study among three widely available sensors, representing the state of the art in the market of both wideband and broadband sensors. Two different earthquake experiments have been used, with magnitudes ML 4.9 and 4.7 and epicenter distances of 200km and 100km, respectively. For each experiment, the waveform and spectrum plots of each vertical channel have been analyzed.

It is shown that, despite the complexity and cost differences, wideband sensors provide superior performance compared to broadband sensors in the range of their recording spectrum, with no loss of any low period information. Coupled with the cost differences, that allow more stations to be installed, the use of wideband sensors is the recommended way to go, for local and regional seismicity as well as micro-seismicity monitoring.

Figure 1. Seismometers in the seismic vault.

1. Experiment Setup

The scope of the experiment was the investigation of the performance of a wide band sensor (WB), in regional  and  local  earthquake  recording.  The  WB sensor was tested against a typical short period (SP) BB sensor while a Broad Band sensor (BB) was used as a reference. The seismic sensors were installed in a seismic vault, for a period of six months, and common WB recordings of local and regional events were extracted SP for analysis. The scope of the experiment was the investigation of the performance of a wide band sensor (WB), in regional  and  local  earthquake  recording.  The  WB sensor was tested against a typical short period (SP) BB sensor while a Broad Band sensor (BB) was used as a reference. The seismic sensors were installed in a seismic vault, for a period of six months, and common WB recordings of local and regional events were extracted SP for analysis.

Figure 2. Event A (left) and event B (right) records from the three instruments.

2. Waveform data

We have used waveform data from two regional events. The first one (Event A), was an ML 4.9 earthquake recorded at an epicentral distance of 200km, the second one (Event B) had a magnitude of ML 4.7 and was recorded at an epicentral distance of 100km. Instrumentally corrected records are plotted in Fig.2. Wide Band (WB) and Broad Band (BB) records are perfectly matched while the Short Period (SP) sensor clearly lacks longer periods, as expected.

Figure 3. Event A (left) and event B (right) records from the three instruments.

2. Results

In Fig.3 the Power Spectral Density plots of the two events, are presented. In both cases the WB and BB records have equal spectral characteristics, even in the low frequency band. As expected, the SP sensor cannot record accurately in the low frequency part.

References 

[1] Sokos, E. N., Zahradnik, J. ISOLA a Fortran code and a MatlabGUI to perform multiple-point source inversion of seismic data, Computers & Geosciences, Volume 34, Issue 8, August 2008, Pages 967-977.

[2] Sokos, E. and Zahradník, J. Evaluating Centroid‐Moment‐Tensor Uncertainty in the New Version of ISOLA Software, Seismological Research Letters, July/August 2013, v. 84, p. 656-665

Geobit’s awarded booth in HAGI 2019

Geobit’s awarded booth in HAGI 2019

Geobit with its Indonesia distributor, PT. Exact Global Teknologi, are exhibiting at the HAGI – IAGI – IAFMI – IATMI Joint Convention 2019.

Our successful participation in the HAGI-IAGI-IAFMI-IATMI Join Convention 2019 gave us the opportunity to meet existing and future clients, present our new instruments and have fruitful and strategic discussions with our Indonesia representatives of PT Exact Global Teknologi.

Our solutions are top-rated in the Indonesia market and currently, we are opening new markets in the structural monitoring of buildings.

Our booth was awarded, as “Best content booth” taking the 2nd place, as A-Class Booth.

Geobit’s distributor in Indonesia, PT. Exact Global Teknologi is an innovative company with deep knowledge on monitoring and exploration projects. They are also trained to provide support and maintenance for our instruments in the whole Indonesian territory. Arry Muharam Manaf and Indra Irawan are always available to discuss for any related project.

GEOsix Low Power Digitizer-Recorder

GEOsix Low Power Digitizer-Recorder

Technical Specifications

  • High resolution digitizer
  • Eight extra analog inputs
  • Eight TTL command lines
  • Low power consumption
  • Dimensions 168x106x68mm
  • GPS time / Precision DPLL
  • 100-500 samples per second
  • 6 seismic input channels
  • Ultra low noise preamplifier
  • Embedded Open Source OS
  • Embedded SeedLink Server
  • Embedded Earthworm Serve
  • Continuous/Trigger recording
  • Advanced functionality
  • Smart Network Operation

GEObit introduces GEOsix series high resolution 6 analogue seismic channels telemetry digitizer / recorders. The size of the instrument is only 168 X 106 X 68mm. The power consumption starts only from 0.8W for 6 channels. Available sampling rate is 100 to 500sps/6ch and optional lower sampling intervals are supported. Built-in GPS receiver combined with ultra-accurate DPLL unit providing time drift 10e-9 sec ensures timing stability even in the absence of GPS signal. NTP timing is also available.

The unit is very flexible and accepts several types of analogue front end units so any type of seismic sensor can be connected. Additionally, it provides eight extra-low resolution and rate analogue inputs for seismometer mass position monitoring, or any other environmental parameter monitoring.

Eight TTL command outputs are supported for seismometer control or for any other external device control. Typically the digitizer supports differential variable gain preamplifier. Our force-balance sensor front end is also supported, providing a wide-band response (10sec – 98Hz) and high sensitivity 1500V/m/s by connecting a C100 sensor. Acquisition parameters and operation modes can be set from the user – friendly web interface.

The unit operates in continuous mode, triggered mode or both and data are streamed through different data ports. Local data storage is selectable as well as logfile information. The unit supports advanced functionality, implemented from the combination of trusted open-source software components. Because of it’s open-source architecture is able to run any custom application thus providing the next day solution to the user. The hardware is based over an embedded ARM9 400MHz ARM linux PC. The data are stored in mini-SEED format into the microSD card. The instrument supports 10/100 ethernet port and debug port. FTP, SFTP, SSH are also available. The state of health is transmitted over UDP packets upon request, and it is logged to SeisNetWatch developed by ISTI.metry.

GEOwarning, Early warning accelerograph

GEOwarning, Early warning accelerograph

GEOwarning

GEObit introduces world’s lowest price, miniature digital accelerograph based on MEMS accelerometer, 20bit digitizer, local data storage and embedded Seedlink and Earthworm Server for data telemetry.

Technical Specifications

  • 3 components miniature Accelerograph
  • Range +/-2g, +/-4g, +/-8g
  • Low power consumption
  • Ethernet and WiFi
  • Dimensions 90 X 115 X 55 mm
  • 20bit analog to digital converter
  • Embedded Seedlink and Earthworm Server
  • Realtime Telemetry and Local Storage
  • MiniSEED data format
  • Linux OS
  • Web Configuration Interface
  • SSH, SFTP,HTTP NTP
  • SPDT relay, software configurable
  • Dynamic Range 85dB
  • STA/LTA, PGA, CAV
  • Operation Range: -20 +70 C
  • Waterproof IP67 Aluminum Case

GEOwarning is a compact, ultra low-cost digital accelerograph.  It integrates 3 axes MEMS accelerometer, 20bit digitizer, embedded linux OS and GPS or NTP  timing. Seedlink and Earthworm servers ensure reliable real time data telemetry while large storage volume ensures a long period of local data recording. The instrument has very low power consumption so it can operate powered from a small 12Vdc battery. Due to its small size and its flexibility of communication (Ethernet or WiFi) and timing (GPS or NTP), it can be easily installed at buildings and other structures.  The device supports a software configurable, variable range of +/-2g, +/-4g, +/-8g  presenting an ideal solution for a wide range of structural monitoring and early warning applications. Minimum data latency along with the calculation of an earthquake’s Cumulative Absolute Velocity (CAV) guarantee that the user can be immediately alerted just at the beginning of the event. Compact design is a competitive advantage and this is reflected in the price which is only a small fraction of the typical commercial accelerograph’s cost. The user is now able to deploy even five times more units for the same budget.