At Sonardyne, we’re dedicated to ensuring the reliability of our equipment for your peace of mind. That’s why we’re offering a specialised health check service for your WSM6+ transponders.
Why a health check?
Maintain original parameters: Ensure your devices stay true to their original specifications.
Consistency with specifications: We check every aspect to guarantee consistent performance.
Prevent deployment damages: Our thorough inspection identifies and prevents potential damages that could compromise your operations
Our promise to you
Preventive care: This is our opportunity to identify any potential issues before they arise, safeguarding your operations.
Detailed report and certification: We provide a comprehensive report and a certificate, confirming the state of your unit.
Value for money: Investing in a health check to keep your WSM6+ in optimal condition will help to: Extend its working life, avoid the cost of delayed / aborted operations due to product failures, delay the cost of replacing equipment.
What does the health check include?
- Comprehensive inspection of all key components.
- Sensor parameters check and adjustment if necessary.
- Tank test and in water performance checks
- Bench and soak testing in control environment.
- Detailed analysis and feedback.
Who do I contact?
Don’t wait until it’s too late! To ensure your transponders are in optimum condition, contact us to schedule your WSM6+ health check today!
What is the preferred mode of operation for SST 6 beacon interrogation?
Sonardyne provide a navigation system called “HydroPos”, and in its early years we suggested that Group Interrogation was the better option. However, we recommend (and implement) Unique Interrogation mode now.
The original idea was that the vessel could sail between two seismic lines, and interrogate multiple beacons during its transit.
This is true – and it worked – but the problem is that, to target multiple beacons, the Range Window needs to be quite large. The result is that the single interrogation from the Transceiver instigates lots of beacon replies, but many of them are too far away to provide useful range data.
Also, the associated Range Wait in the topside equipment means that the most important beacons (which are nearest the vessel) only provide a relatively small number of ranges (because the Transceiver is waiting for all the other replies to arrive before the next acoustic cycle).
The best approach is to use “Unique Interrogate” mode.
Set the Range Gate to a modest value so that you focus on only 1 to 3 beacons at a time. The associated Range Wait time will be much smaller, and the result will be a much larger, and more useful set of range data.
In the example below, Address 11329 means this:
1 = “Nodal” architecture (always 1)
13 = Group Interrogation Address
56 = Group Reply Channel
However, when used in “Unique Interrogate” mode, this is what happens:
Transceiver sends Unique Interrogation Channel 1356.
SST 6 receives this, then waits 320ms (Turn-Around-Time).
SST 6 transmits Group Reply Channel 56.
When Compatt 6+ transponders are deployed, they can be installed at varied heights off the seabed depending on the method of deployment (stands, floats, etc).
Stands offer greater stability but are restricted to typically 2-3m height off seabed, whereas floats allow the Compatts to be deployed much higher off the seabed.
There are several reasons why you would install Compatts higher off the seabed, these include:
- Improved visibility between Compatts
- Avoid undulating topography
- Increased maximum range between Compatts
We use specialist software, RayTrace, and sound velocity profiles from worksites to determine the optimum Compatt height off seabed. Sound waves move towards lower velocity areas so ray paths bend in the water column. RayTrace allows an estimation of the maximum achievable baseline range and presents this in graphical form. See below the images from RayTrace software which shows how height above the seabed affects the maximum Compatt to Compatt range. The first image demonstrates Compatts 2m off seabed with a 1200m maximum separation, compared to the second image where the Compatts are 5m off the seabed and can achieve over 1800m maximum separation.
However, using floats means that there will be slight movement (deflection) of the Compatts due to ocean currents. Sonardyne performed an analysis of deflection of low drag and square sided floats to determine the amount of movement at different length strops (height above seabed). The full results of this study can from [email protected].
