High Frequency Introduction
SEIS-UK has 36 Polar Pegasus PGS-140-XC broadband data loggers. These data loggers are compact, light weight and low power equipment capable of storing analog input from a variety of external sensors including seismometers, accelerometers, tiltmeters and other geophysical sensors. SEIS-UK maintains 3-component GS-ONE geophones for use with the Polar Pegasus. SEIS-UK's previous high frequency instrumentation was the RefTek 130-01 and GS11-D 4.5Hz geophones. Details about both data loggers and geophones can be found below.
Specification, Polar Pegasus Datalogger
| Total number | 36 |
|---|---|
Digitiser |
24 bit ADC per channel |
Data output |
Waveform and SOH: miniSEED Metadata: StationXML |
Memory |
32 GB internal data storage |
Data download |
Data is downloaded using a USB 3.0 to Data Harvester (1TB) or a laptop |
System control |
Bluetooth connectivity with mobile app for config, live view, and SOH. |
Power consumption |
<200mW |
Power supply |
12V (9-17V DC range) |
Dimensions |
83.5mm x 96.5mm x 164mm |
650g |
|
Sampling rate |
1000, 500, 250, 200, 100, 50, 40, 20, 10, 5, 2, 1 sps |
Operating temperature |
-45°C to 60°C |
GPS |
External GPS antenna |
Specification, 4.5 Hz GS-ONE Geophone
| Total number | 40 |
|---|---|
Natural frequency |
4.5 Hz |
| Spurious frequency | 120 Hz |
Open-circuit damping |
0.42 ± 0.1 |
Open-circuit sensitivity |
2.55 V/in/sec |
Sensitivity with 20kΩ load |
2.27 V/in/sec |
Coil resistance |
2450 Ω ± 5% |
Approximate useable bandwidth |
4.5-1000 Hz |
| Dimensions (within casing) | Width 100mm, length 110mm + cable, height 800mm (without spikes), 1500mm (including spikes) |
| Weight | |
Operating temperature |
-40°C to 80°C |
Specification, RefTek Datalogger
| Total number | 18 |
|---|---|
Digitiser |
Integral 24-bit |
Data output |
Reftek Format |
Memory |
4MB battery backed SRAM, plus two removable CFII cards with 16Gb capacity. |
Data download |
Data from the removable flash can be read on a PC using a USB card reader supplied by SEIS-UK. |
System control |
Via iPod device with iFSC app |
Power consumption |
~1W for 3 channels of recording, continuous GPS and no communications |
Power supply |
10-16V DC |
Dimensions |
135mm x 185mm x 353mm |
2kg |
|
Sampling rate |
1000, 500, 250, 200, 125, 100, 50, 40, 25, 20, 10, 5, 1 sps |
Operating temperature |
-20°C to 60°C |
GPS |
External GPS antenna and internal high precision TCXO |
Specification, 4.5 Hz GS-11D Geophone
| Total number | 18 |
|---|---|
Natural frequency |
4.5 Hz |
| Spurious frequency | |
Open-circuit damping |
0.34 |
Open-circuit sensitivity |
0.81 V/in/sec |
Sensitivity at 70% damping |
0.664 V/in/sec |
Coil resistance |
380 Ω |
Approximate useable bandwidth |
4.5-1000 Hz |
| Dimensions (within casing) | Width 100mm, length 110mm + cable, height 800mm (without spikes), 1500mm (including spikes) |
| Weight | |
Operating temperature |
-40°C to 80°C |
Shipping information
All the high-frequency systems ship in aluminium Zarges cases containing a datalogger, a geophone, solar regulator, GPS antenna, all required cabling and a bungee cord.
Power supply will be dependent on survey design and location. Batteries must be provided by the user, whilst solar cells (if used) may be available from SEIS-UK up to a reasonable capacity.
SEIS-UK is able to offer advice on the appropriate number of solar panels and batteries necessary for your deployment period and location.
| Instrument box dimensions | 600mm x 390mm x 400 mm |
|---|---|
| Instrument box volume | 0.9 cubic meters |
| Instrument box weight | ~11kg (including contents) |