Technical Services

1. Field Surveys, Data Processing & Analysis
_ Ex:
4D/3D/2D resistivity profiling=>One-Shot Resistivity
Passive/Active Surface-Wave Survey=>
Linear Array Microtremor Survey
PS-logging, Q-value analysis
Marine Surface-Wave Survey

2.Geo-Monitoring
_ Ex:
Resistivity monitoring=>One-Shot Resistivity
Vibration/displacement monitoring
Earthquake monitoring=>
Seismic/Microtremor Network System
3. System & Application Software Development
_ Ex:
Acquisition/monitoring systems
Earthquake observation networks=>
Seismic/Microtremor Network System
Data processing application software

4. Sensor tests
Vibration sensor test by Portable Shaking Table
Geophone test by Step Function Test

5. Literature reserch
Abstracting
Technical translation (Jp <=> Eg)


Real-Time 4D Resistivity Surveys Come True!!
By utilizing our CDMT (Code Division Multiple Transmission) technique we offer data acquisition at unprecedentedly high speeds with high accuracy.
Typically, we can collect data from 24ch transmitters × 24ch receivers simultaneously within 10 seconds.
 
Data acquisition system for 24ch transmitters × 24ch receivers.

Increasing the number of both transmitter and receiver channels is possible.
This CDMT technique allows us to:
・perform Real-Time 4 Dimensional Surveys
・display such dynamic phenomena as groundwater flows during liquefactions and landslides.

obtain better quality data than conventional systems.
Our services include customizing & developing your CDMT resistivity measurement system.


Vibration Sensor Test by Portable Shaking Table

Are your vibration sensors up to standard?
Using our own original Portable Shaking Table, we can carry out accurate tests for Accelerometers, Geophones and Seismometers at low cost.
The Portable Shaking Table is small and light weight employing one axis actuator.
 

Advantages:
 
・Low cost checking at frequecy range of 0.01-15Hz
・Outputs of not only amplitude but also phase responses
・One axis actuator utilizing micro-step-control motor allows extremely smooth shaking at especially very low frequency range.
・Its small size and light weight make it possible to perform on-site test. It only requaires a spaces of SOcm x SOcm and a 1OOVAC power supply.
・Not only holizontal shaking but also vertial shaking is available



You can order a Portable Shaking Table itself for your own inspection.



Seismic/Microtremor Network System

4DGeoTek offers ideal vibration monitoring systems using sensors and acquisition & communication systems most fit for task
4DGeoTek is able to provide clients with a One-Stop-Solution for comprehensive plans to develop and install seismic/microtremor network systems.

All-in-one seismometer GeoSIG GMSPlus-73-WiFi
It integrates force balance accelerometers, 24bit digitizers, a computer, a GPS a ntenna and WiFi.
 

Advantages:

・Advanced network system utilizing the all-in-one high performance seismometer GMSPlus-73-WiFi
・Calculations equivalent to JMA Instrumental Seismic Intensity
・Real-time compensation for low frequency geophone response
(up to 1/10 of natural frequency)
・Rapid software development based on LabVIEW
・Improved S/N through application of Singular Value Decomposition /Kalman Filter






GMSPlus-73-WiFi is available for sale separately if you want to include it to your own network.



Linear Array Microtremore Survey (LAMS)

One of the most cost-effective and widely applicable surface-wave survey methods
LAMS technique can accomplish deeper investigation depths up to approx. 1OOm (depending on S-wave velocities and max. array sizes) using 4.5Hz geophones in comparison with MASW* .
Note* : Multi-Channel Analysis of Surface-Waves

2 dimensional surveys are a practical use of LAMS (20-LAMS)
.
Example of S-wave velocity section obtained by 2D-LAMS
-Result compared with a seismic section obtained by Reflection Survey -

c


 Advantages:

・No additional equipment required other than that used for MASW.
・Tolerance of traffic vibration noises is very high.
・ Integrating 2D-LAMS and MASW allows for the acquisition of Vs sections combining both high resolutions and deep investigation depths.