The SSBL principle has the obvious advantage that it only requires installation of one hull mounted transducer and one subsea transponder to establish a three-dimensional position of the transponder. An SSBL system is measuring the horizontal
and vertical angles together with the range to the transponder. An error in the angle measurement causes the position error to be a function of the range to the transponder. To obtain better position accuracy in deep water with an SSBL system it is necessary
to increase the angle measurement accuracy.
HiPAP 502 system configuration drawing. Click on image to view larger version.
The HiPAP 502 High Precision Acoustic underwater Positioning and navigation system operates with the transducer mounted on a hull unit to allow the transducer to be lowered some meters below the hull of the vessel. A Transceiver Unit containing transmitter,
preamplifiers and beam forming electronics is mounted close to the hull unit. The system can be configured with one or two hull mounted transducers. With the use of two transducers, accuracy and redundancy will be improved.
HiPAP 502 transducer
The HiPAP 502 High Precision Acoustic Positioning system has a spherical transducer with several hundred elements covering the whole sphere under the vessel.
The system will dynamically control the beam so it is always pointing towards the transponder. The transponder may be moving, and roll, pitch and yaw affect the vessel itself. Data from roll/pitch sensors are used to roll and pitch compensate the position.