Ship mobilization

The exercise was conducted jointly by NORBIT and our official reseller for Malaysia, Geohydrocean Services Sdn Bhd (GHOS) between May 4-8, 2021 in Malacca, Malaysia.

A vessel of opportunity was found on site and quickly mobilized within hours with the NORBIT WINGHEAD system. The NORBIT WINGHEAD is integrated with an OceanMaster GNSS/IMU POSMV system and is transported in two 21″ pelican cases, complete with cables and Sonar Interface Unit (SIU).

[Link][Link]Assembly[Link]

The twin-head system was mounted on a sideways aluminum pole mounted on a swivel attached to the vessel. The ship was about 9m long and 2.5m wide.

The NORBIT WINGHEAD was mounted on a 37.5° angled NORBIT stand with the receiver array facing forward. An optional 10° angle is also available.

Real-time positioning was achieved using the Marinestar G2 DGNSS signal fed directly into the OceanMaster POSMV module. The position data has been further enhanced during post-processing using the Applanix PP-RTX solution and the depth is based on the EGM96 geoid model.

Calibration

The NORBIT WINGHEAD is a multibeam integrated with the Applanix POSMV OceanMaster GNSS/IMU system. Instead of performing multiple stand-alone calibrations to determine the heading alignment of the gyrocompass, only one heading alignment was performed in the NORBIT GUI software.

The purpose of the heading alignment calibration is to determine the fore-aft mounting error of the two GNSS antennas based on the IMU reference plane. The separation between antenna 1 and antenna 2 is 2 m, as measured on the mounting pole.

Correction values ​​derived from heading alignment calibration are stored in the POSMV system.

Although the POSMV IMU is rigidly mounted in the NORBIT WINGHEAD transducer housing, a patch test is still recommended to determine minute mounting errors and especially in a dual head mount, to determine the angle of actual inclination of the support (37.5°).

A patch test is performed for each transducer to determine the mounting error of each transducer. Results derived from the patch test are used in data processing in CARIS.

Sea trial methodology

An interesting seabed feature was also probed to demonstrate the high resolution capability of the NORBIT WINGHEAD system.

  • Rocky outcrop about 13m high in 20m of water with the highest point of the outcrop about 10m deep.

  • An exposed pipeline is visible about 200 m to the southeast with an NS alignment.

  • There appears to be a strong current flowing in a NW/SE direction as observed from the outcrop and exposed pipeline.

  • Several linear streaks can be observed in the same direction of current flow.

  • Note that the depth refers to the EGM96 geoid model.

[Link][Link]

Conclusion

The NORBIT WINGHEAD is a versatile high-resolution Multi-Beam Echo Sounder (MBES) designed with scalable capability to meet future requirements. The design platform allows for expansion with future technological advancements.


As the NORBIT WINGHEAD is a compact MBES, it is easily transportable by any form of commercial transport and deployed on any vessel used with either a locally fabricated side mast or the NORBIT PORTUS mast.


For a more permanent installation, a hull mount configuration is available with a stand-alone OceanMaster IMU POSMV installed on the center of gravity (COG) of the vessel.

As demonstrated in sea trials, the NORBIT WINGHEAD is capable of delivering high daily production throughput, minimizing vessel operating hours on site while providing high resolution seabed mapping in a compact system, especially with NORBIT data acquisition software (DCT).


For more information on dual head tape coverage, please contact NORBIT.

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