TECHNICAL DESCRIPTIONS OF INSTRUMENTS USED IN ISTANBUL RAPID RESPONSE and EARLY WARNING SYSTEMS

 

The system is designed by Kandilli Observatory and Earthquake Institute of  Bogazici University.  The construction of the system is realized by the GeoSig Inc. (http://www.geosig.com)  and Electrowatt-Ekono (www.ewe.ch) consortium. Communications of related Rapid Response data,  are provided by ARIA GSM  (http://www.aria.com.tr) service provider.

 

 

 

 

A GSS strong motion accelerograph  utilized in the IERREW system.

 

 

All of the Rapid Response (Dial-up), Early Warning (On-line) and Structural Monitoring (Off-line) stations will use essentially the same instrumentation package that will consist of following units.

 

 

 

 

 

 

Sensor

 

External, tri-axial (three orthogonal axis), force-balance (servo) type accelerometer

Range: +/- 2 g full scale (optionally adjustable)

Dynamic Range (Minimum): 108 dB (Dial-up and off-line), 144 dB (On-line)

Frequency Range: Flat between 0 and 50Hz (minimum)

Damping: Between 0.6-0.7 (Critical)

Linearity: 1% (minimum)

Cross axis sensitivity: 3dB-RMS (minimum)

 

 

 

 

                                                                       Guralp CMG5T transducer

 

 

 

 

 

Digitizer/Recorder

 

Sampling: Selectable up to 200 (minimum)  samples/sec./channel with anti-alias filtering

Resolution (minimum):  18 bit (Dial-up and off-line),  24 bit (On-line)

Pre-event memory: 30s (minimum) selectable, at maximum sampling rate

Post-event memory: 60s (minimum) selectable, at maximum sampling rate

Recording Media: Memory Card with (minimum) 60 minute recording time at maximum  sampling rate

Triggering: Threshold and LTA/STA (optional)

Parametric Information:  Instrumental Parameters, Peak Ground Acceleration, Event  Duration, Spectral Acceleration (optional), Spectral Intensity (optional)

 

 

Communication Module

 

RS-232 based remote interrogation

For On-line stations: Spread Spectrum digital radio modem.

For Dial-up stations: GSM Modem (Data link and SMS) using Siemens M20 compatible specifications.

 

 

Timing Module

 

Standard internal clock

Integrated GPS timing to provide UTC time, clock correction and position (for all units).

12 Channel reception with 5 microsecond (minimum) resolution.

Separation with the station (if needed): 70m (minimum).

 

 

Power Supply

 

External charger voltage: 220 (+/- 20%)

Solar Panels for 4 (four) of the On-line stations

12V internal battery that can provide (minimum) 72 Hour autonomy

Provision for connection of 12 V external car battery