GROPLAN project is founded by the French Research Agency, with a partnership composed of the French Research Institute CNRS with the LSIS Laboratory specialized in informatics and model, the French company COMEX specialized in underwater engineering and research, and archeologists from the Malta University, CNRS Camille Jullian laboratory and Texas A&M University. GROPLAN is a project for 4 years and the Malta campaign represents the main sea campaign to collect data to be used during the project. This campaign is included in the work package 5 managed by COMEX. The MINIBEX vessel with all the equipment required to collect the 3D data on the XLEDI wreck in Malta leaves Marseille the 10 July to be ready to start the campaign the 16th.
Minibex is a light, highly maneuverable 30 meters vessel fitted with a Dynamic Positioning system, allowing research and subsea operations down to 800m. Minibex offers an outstanding ratio between mobility, reduced crew and onboard equipment. The “DP” designed by COMEX allows the ship to remain stationary above a fixed seabed reference point, to keep a constant heading or to follow free swimming or tethered, mobile target accurately. MINIBEX is equipped to provide comfortable living conditions for 11 persons. Thanks to her high level of automation and sophisticated equipment, a multidisciplinary team can operate a wide range of underwater scientific or oceanographic equipment and subsea exploratory vehicle. While of moderate size compare to more conventional oceanographic vessels, MINIBEX offers a far higher cost/value ratio with increased mobility, reduced crew, safe handling and wide range of equipment.
|Surface positioning system – DGPS||Subsea positionning – USBL|
DGPS AG132 - TRIMBLE
HPR 410P – SIMRAD
|The TRIMBLE AG132 is a DGPS with sub metric accuracy. The AG 132 can use a technology which is the combination of the beacon differential, satellite differential and WAAS/ EGNOS differential receiver.||To positioning Side Scan Sonar, ROV or submarine, a subsea positioning system is required.
The system used on the MINIBEX vessel is an Ultra Short Base Line (USBL) HPR 410P from SIMRAD. |
A transponder is fitted close to the Side Scan Sonar Towfish or on ROV, Submarine, depending of operations. All records will geo-referenced in real time.
|SUPER ACHILLE ROV||REMORA 2000|
|Our SUPER ACHILLE, in place on board MINIBEX, is a light observation ROV (80 kg) fitted with a Tether management system that enables it to operate quickly at a depth until 800 m. It is equipped with two video color cameras, one 3 axes working arm and a Tritech panoramic sonar.
In function of needs, It can be fitted out with specific tools, to perform: research, inspection, observation, sampling, subsea movie, divers assistance, recovery of wrecks, etc…|
DYNAMIC POSITIONING AND TMS : The optimal solution. Super Achille is a turnkey solution composed by:
|The latest in the range of COMEX’s innovative submarines, REMORA 2000 combines the functions and instrumentation of an oceanographic subsea vessel with the built-in amenities and eye-catching design of a recreational submarine
Its primary mission is to carry two persons down as far as 610 meters for up to 5 hours of underwater exploration in the comfort and safety of an air-conditioned cabin at atmospheric pressure. |
|The ROV3D system is very high resolution optical survey system. Two types of sensors can be used, dependant of the size of the site, merging acoustical data and optical data to produce a 3-dimensional model of a large and complex underwater site. |
There is two step of survey :
Production of an acoustic model by a high frequency acoustic: 3D scanner. Multiple stations around the site are merged to model the interest site. This step is done only in case of large area study.
Optical survey using 3 cameras to produce very high resolution 3D data.
These two models are merged to build a 3D reconstruction of large complex scenes, the ROV3D system can be operated by the submarine REMCRA 2000 or a ROV (ROV APAG-IE).
A navigation system based on real tine odometry process and included into the RO\/3D system give to the operator a real time trajectory of the vehicle.
The software suite include:
Over the past years, local heritage authorities in Malta have conducted a number of systematic remote sensing surveys off the coasts of the Maltese Islands. One such collaborative project resulted in the discovery of a well-preserved ancient shipwreck. From initial studies conducted on the site it was established that the site is datable to circa 7th century BC at a depth of 125 m. This shipwreck may offer new and significant information about Phoenician seafaring and trade in the central Mediterranean during the archaic period. To date, little is known about the earliest contact of Phoenician mariners with the Maltese islands. Most archaeological evidence stems mainly from funerary evidence. This discovery may be considered as one of the best-preserved archaeological sites in Malta datable to the early Phoenician period. The use of a remote operated vehicle, side scan sonar and a sub bottom profiler enabled the discovery, study and assessment of this deepwater shipwreck. Preliminary photomosaics were created and video footage obtained. Importantly, it was also established that the bulk of the cargo still remains buried in the sediments.
Recently discovered, the Xlendi wreck on approximately 120m depth shows on the top part a freight well preserved, composed by amphorae and millstones which reminds off a 12 – 14 meters by 4-5 meters vessel. Some images evoke a second level of amphorae. The exam of the first level shows a mixed freight and the vessel seems entire. From the information the archaeologist have, the ship wreck is dated between the end of the VIIIe century and the middle of the VIIe century before J-C. This configuration is perfect for a photogrammetry studies, in fact, the photogrammetry will permit to provide a 3D reconstitution of the first level, in order to pick up amphorae and millstone to provide studies on. The operation was composed:
Pilot Y. Tchernomordick – Co-Pilot and ROV3D: B. Chemisky
The REMORA 2000 equipped with ROV3D system has been deployed for the first survey the 17/07/2014 at 10:30am
The survey begun at 11:00, 8 passes E-W and 6 passes N-S and the record finished at 12:20.
The camera has been disposed at the vertical of the site.
The second survey has been done the 18/07/2014, the camera has been disposed at +22.5° and the survey begun at 11:29 and finished at 12:25. 10 transects E-W and 8 transects N-S