LotOBS
From the 2004 version of the MicrOBS, we have developed equipment capable of recording 1 to 4 components (one hydrophone + three short-period geophones) for 4 months with a 6-month deployment. An update should allow us to achieve a 12 month monitoring period in 2020.
The LotOBS characteristics are similar to those of the MicrOBS, the main modifications are:
- storage capacity 62 Go instead of 8;
- clock precision around 2.10-8 instead of 3.10-8;
- the geophones are located outside the sphere in direct contact with the sediment.
General | Maximum depth | 6000 m. |
Weight in air | 50 kg | |
Weight in air with ballast | 75 kg | |
Weight in water | - 8 kg | |
Weight in water with ballast | 17 kg | |
Dimensions (H/L/W) in mm | 700 / 550 / 550 |
Sensors | 4 components | 1 hydrophon & 3 geophones |
Hydrophone sensitivity | - 160 dB ref. 1 mV/microPa | |
Hydrophone LF-3dB | 2 Hz | |
Hydrophone full-scale signal | 70 Pa | |
Geophones | 3 axes | |
Geophones type | 4.5 Hz (-3 dB) | |
Geophone sensibility | 22.4 mV/mm.s-1 | |
Geophone full-scale | +/- 0.38 mm.s-1 |
Acquisition | Seismic channel | 4 |
Resolution | 24 bits | |
Sampling frequency | 25 à 250 Hz | |
Measurement bandwith | DC to 0.40 x f sampling | |
Preamplifier gain | Variable from 1 to 64 | |
Clock | 3.10-7 (0.3 ppm) or 5.10-8 | |
Correction of clock drift | linear drift correction | |
Synchronisation interface | DCF 77 (GPS signal) | |
Storage | 32 Go (IDE SSD disk) | |
Configuration interface | RS232 (9 600, 1, 1) |
Energy | Alcaline or lithium pack | Li-Ion battery |
Electric consumption | 0.7 W recording, 0.3 W low power | |
Autonomy | Recording 4 months Deployment 6 months |
Release | Width | Titanium mini-release + electronic integrated release |
Acoustics | Seismic hydrophone | |
Maximum depth | 6 000 m |
Localization | Flash | Novatech (ST 400-A) |
Gonio VHF | Novatech RF700A-1VHF 156.625 MHz |
