KONGSBERG HiPAP System Operation and Maintenance Guide

Sensor offset: Input GNSS antenna MRU、 The lever arm of the electric compass relative to the reference point of the ship. APOS will be uniformly converted to the ship coordinate system.

5.2 Deployment and activation of responders

When using cSIDE responder:

Activate the dormant responder by sending the "Wake Up" command through HiPAP.

Assign unique channel numbers (1-106, including 56 traditional channels and 50 Cymbal extension channels).

Set the transmission power level of the responder, balancing battery life and maximum operating distance.

For LBL arrays, use the "LBL Translator Positioning" function to automatically measure the baseline and establish the array.

5.3 Data Display and Output

APOS graphical interface provides:

Horizontal position diagram (top view of the ship relative to the transponder or array)

Depth profile (vertical section)

Historical trajectory (adjustable storage interval)

Digital data display (coordinates, distance, angle, signal-to-noise ratio, etc.)

When transmitting data to the DP system, the following options can be selected:

Raw location data (output per ping)

Smooth position after Kalman filtering (recommended for DP)

Common troubleshooting and on-site diagnosis

6.1 Fault 1: Unable to receive responder signal ("No Reply")

Phenomenon: APOS shows that the interrogation has been transmitted, but there is no effective echo from the responder.

Possible reasons:

The responder is not turned on or the battery is depleted.

The channel number does not match.

The transducer is blocked (covered by bubbles, marine organisms, or sediment).

Sound bending causes the beam to not point towards the responder.

The responder has exceeded its maximum operating distance.

Solution steps:

Check if the responder is in the "Active" state in the APOS "Translator Status". If not, try sending a forced wake-up command.

Confirm that the responder channel number is consistent with the APOS settings (including Cymbal and traditional mode).

Check the surface of the transducer: If the hull unit has been raised, visually inspect for any attachments. Diving for cleaning if necessary.

Check the noise spectrum analyzer (APOS built-in function): if the ambient noise in the frequency band is too high (such as nearby construction, ship propeller cavitation), try to reduce the speed or move the operation area.

Input the accurate sound velocity profile and observe whether the beam deviates beyond the mechanical inclination range of the transducer due to refraction.

Gradually increase the transmission power of the responder (be careful not to exceed the maximum rated value).

6.2 Fault 2: Positioning jump or abnormal dispersion (poor accuracy)

Phenomenon: The position display of the responder is unstable, jumping several meters in a short period of time.

Possible reasons:

MRU data loss or low accuracy.

Electric compass data interruption or delay.

Multipath interference (from ship bottom, water surface reflection, or steep seabed slopes).

The installation angle calibration of the transducer is inaccurate.

Solution steps:

Check the "Sensor Input" page of APOS to see if the Heading, Roll, and Pitch are updated at ≥ 10Hz. If the value is stationary, check the serial communication or the sensor itself.

Turn on 'Ray Tracing Display' in the graphic view and observe if there are any noticeable peaks in the reflected waves. If there are multiple paths, you can try disabling automatic gain control and manually setting a lower gain to ignore reflected waves.

Re execute automatic transducer alignment calibration. If mechanical deviation is suspected, it can be verified using a water surface responder at a known location.

Enforce the use of Cymbal protocol (if available), which has stronger multipath suppression capability in its spread spectrum encoding.

For LBL mode, check if the baseline measurement of the array is correct and if there is any responder position drift.

6.3 Fault 3: Failure of heave compensation or incorrect display of water depth

Phenomenon: The depth value of the responder deviates significantly from the actual deployment depth, or it shakes violently with the ship's rise and fall.

Possible reasons:

The depth sensor of the responder is not calibrated or faulty.

APOS is not connected to the correct sound velocity value.

The vertical reference of MRU is incorrect.

Solution steps:

Compare the depth displayed by APOS with the actual deployment depth of the responder (such as the winch counter). If the error exceeds the theoretical value of "sound velocity error x slant distance", first check the sound velocity profile.

If the responder has a built-in pressure sensor, the raw pressure value can be read and the zero point calibrated through APOS' Read External Sensor '.

Confirm whether the Heave data output by MRU is reasonable: it can be compared with the shipborne wave meter on a still water surface. If the MRU experiences drift, refer to the calibration steps for MRU 5 mentioned earlier.

6.4 Fault 4: Communication interruption between APOS and transceiver unit ("Transceiver Lost")

Phenomenon: Communication error displayed on the operation station, unable to control transmission or reception.