VENUS Geomagnetic and Electric Fields Observation System
VENUS : "Versatile Eco-monitoring Network
by Undersea-cable System"
| VenusOBEM Top | Specification || Dry Dock Test || Deepsea Landing || Deployment and Connection |
Dry Dock Test (July 12-15, 1999, at Misaki-Senpaku-Kogyo Co.Ltd.)
(Photo-1) Top view of "Geomagnetic and Electric Fields Observation System"
Interconnection cable (length : 300m) wound round the drum on the left is extended by ROV toward the branching unit, and the system is connected with the junction box using the shorter part of cable (about 30m) on the side of the drum, which is dragged out in this picture.
(Photo-2) Dry Dock Test in 1999
Performance of contolling equipment and data transmission was confirmed. Acquired data include artificial noises owing to unavoidable circumstances of the test site. In the similar test in 1998 at the same site, large electric field out of measurement range was detected at the electrode spacing of around 2m, and shorter electrode spacing was adopted this time.
3 electrodes are put together in a bundle at the fore side as seen in the picture.
There are 3 electrodes A,B and C, where the 2 component potential differences A-B and C-B are observed. 3 electrodes are bundled in the order of A-B-C, and the electrode separation is about 20 cm for each component. The observation data revealed an anti-parallel variation between 2 components, and also variations correlated with the ones of magnetic field by the fluxgate magnetometer, which suggests the valid function of the equipment.
Sample record of Dry Dock Test in 1999
(Photo-3) General view of test site
The dock was filled with sea water during the over-night operation test. The picture shows the situation of inspecting equipments, when sea water was mostly pumped out.
The top of picture is the toll bridge connecting Jogashima Is. with Misaki.
| VenusOBEM Top | Specification || Dry Dock Test || Deepsea Landing || Deployment and Connection |