Kongsberg HiPAP 101, Product Description, Page: 41 / 87

Product Description
317748/F 33
8 POSITIONING PRINCIPLES AND
PROCESSING
The HiPAP® system uses two different principles for
positioning; the SSBL and the LBL. These two principles have
different properties that make the system flexible for different
applications.

The SSBL principle is based on a range and direction
measurement to one transponder, while the LBL principle is
based on range measurements to minimum three transponders
on the seabed.

The position accuracy in SSBL is proportional to the slant
range to the transponder, while the LBL accuracy is
determined by the geometry of the seabed transponders array
and the vessel that is being positioned.

The SSBL principle, due to its simple operation, is the
obvious choice if the accuracy is good enough for the
application performed. The LBL principle is the obvious
choice if the SSBL accuracy is not good enough for the
application performed, though it requires a more complex
operation.

Cymbal is a signal processing technique used for all
positioning modes. Cymbal utilizes Direct Sequence Spread
Spectrum (DSSS) signals for positioning and data
communication. DSSS is a wide band signal. The Cymbal
protocol provides new characteristics for both positioning and
data communication.
8.1 SSBL positioning
In SSBL, the system calculates a three-dimensional subsea
position of a transponder relative to a vessel-mounted
transducer. The position calculation is based on range and
direction measurements to one transponder. The onboard
transducer transmits an interrogation pulse to a subsea
transponder, which then answers with a reply pulse. When using
a responder the interrogation is replaced by a hard wire trigger
connection.

The onboard system will measure the time from the
interrogation to the reply pulse is detected and use the sound
velocity to compute the range.