F.A.Q

New and innovative technology often comes with a lot of questions. Please see below for an overview of questions we get asked the most. Can't find the answer to your question below? Feel free to contact us, we are happy to think along!

  • Is there not a Doppler radar required for wave & ship motion prediction?

    This is the single, most often heard question. There are other parties offering similar solutions using specially developed Doppler radars (also referred to as 'FMCW' or 'coherent radar').

    However, the answer to this queston is: "No, there is no need for any special type of radar for wave and ship motion prediction."

    All our deployed systems so far use conventional X Band pulse radar technology. See the match of predicted and measured motions for yourselves in one of our videos.

  • Yes, there is one benefit of using Doppler radar: when using Doppler radar you can bypass the step of scaling the predicted motions based on recent motion history.

    However, wave and ship motion prediction technology is most useful when a ship is working near its motion limits. Since the ship is set in motion by the waves and scaling by recent motion history is practically always possible. For that reason, in our view, using a specialised Doppler radar is not worth the additional expenses.

  • In case a conventional X Band radar is sufficient and no Doppler radar is required, why are you offering a specialised dedicated radar?

    The specialised dedicated radar we offer is not a Doppler radar. It is a conventional X Band radar with one major difference to the navigation radars you will find on most vessels: the antenna is vertically polarised.

    A vertically polarised antenna does not mean that the antenna is revolving in another plane or alike. See it as a polarisation filter in sunglasses. These filters help to reduce the scattered sunlight when you're on the water. In the same way vertical polarisation of a radar antenna helps to increase the amount of radar energy scatter on the sea surface. This increases the radar data quality for the purpose of wave analysis and wave and ship motion prediction.

    Installing a dedicated radar has another advantage: there is no conflict in use as the radar is solely used for wave monitoring and wave and ship motion prediction and not for navigation. Mostly the combined use of the radar for these two purposes is not an issue but it can be at times.

    Furthermore, dedicating one radar specifically to the purpose of wave analysis and wave and ship motion prediction allows for some further cherry picking in terms of what radar features are best for this purpose. Nevertheless, our radar hardware maintenance is all but fancy stuff: spare parts are common of the shelf goods and the equipment can be serviced by technicians around the world not requiring any special Next Ocean technician training of some sort. All to keep the cost of ownership of the advised and offered dedicated radar as low as possible.

  • In some occasions wave and ship motion prediction technology is of interest for application on board e.g. jack-up vessels. Scaling by vessel motions is problematic in that case.

    Luckily there is a simple remedy for this problem. The WavePredictor can tap into the feed of the (mostly already available) downward looking wave gauge or air gap gauge. When the update rate of this device is suffient the WavePredictor will provide scaled wave predictions to the user.

  • The WaveAnalyser requires roughly 0.5m of significant wave height to work. For the WavePredictor, the minimum required significant wave height is somewhat higher at roughly 1.5m and above.

    For both products however, wind speeds of at least 3Bft are required to ensure sufficient sea surface roughness for the radar to 'see' the waves.

    Furthermore there are requirements on which radar hardware can be used. Read more on this in the 'Hardware' tab in the 'Products' section.

  • No, when the radar does not have a free view into the direction of where the waves are coming from, it is not possible to predict the waves or the motions resulting from these waves.

    In case the structure blocking the radar's view is a so called 'open structure' (think of jacket or alike) it might still be possible for the WavePredictor to perform sufficiently enough for display of predictions to the user. This however depends on the specific situation.

    In some cases, the problem of a 'blind sector' due to a ship-fixed structure is solvable by tapping in to the data feed from a secondary radar. Dual radar support is currently under development.

  • The performance of the product depends on the type of ship and the environmental conditions in which she's operating.

    E.g. short crested waves in confused seas tend to be more difficult to correctly predict than long crested swells. However, sometimes the ship acts as a 'filter' by itself, only reacting to those longer swells, even making it possible to achieve far-ahead accurate predictions in highly confused seas.

    As a ballpark figure you can expect 1 to 2 minutes of accurate predictions when operating near the motion limits of most ships. So far, the furthest we have achieved in terms of accurate motion predictions is 210s, or 3.5 minutes ahead of time(!).

  • There are other motion forecasting solutions available indeed, that forecast motions hours and even days ahead. These services forecast motions in a 'statistical' sense, and not in a 'deterministic' way.

    These kind of solutions are very useful as well, in situations such as mission planning for example (take a look at the website of our friends at MO4: www.mo4.online). However, the information that is provided is fundamentally different.

    A metaphor we often use is the difference between a weather forecast and precipitation radar. The weather forecast might tell you there is a 50% chance of rain showers today, but it doesn't tell you when the next rain shower will be. The percipitation radar however can tell you when the next rain shower will pass by, but it is unaware how the weather will look like tomorrow.

    The WavePredictor is like the percipitation radar. It provides a prediction for the upcoming extremes and quiescent periods in the wave train based on measurements by the X Band radar of the sea surface in the direct vicinity of the vessel.

    This type of information enables operations in conditions that are even 15% to 20% above the conventional operational limits of your vessel. That is some interesting information to take into account again when setting up your mission planning solution.

  • There is always one most critical moment in any offshore operation. This could be e.g. the initial load transfer in a heavy lift operation, the lowering of delicate equipment like ROVs through the splash zone or a moonpool, or the crossing of technicians over a motion compensated W2W gangway. Often these most critical moments tend not to take too long. A gangway crossing takes roughly 30 seconds and even the heaviest ROVs are lowered through the splash zone within minutes.

    The conventional appraoch is to determine limiting wave conditions for these kind of operations. These limits are based on statistics. Only when the chances of a limit crossing event are sufficiently low, performing the critical step is allowed. This can only be achieved by applying significant safety factors. To make things worse, the chance of encountering this limit crossing wave during your critical operation is still there...

    When using the WavePredictor during the most critial part of your offshore operations, things change. There is no need for determining whether a situation is workable or not based on wave statistics. The WavePredictor will simply indicate the exact moments in time where the upcoming motions are below limits. The only remaining question is: how often do these safe windows occur?

    Well the answer is: pretty often! When operating exactly at the conventional operational limits these safe windows make up well over 99% of the time. And since not every wave is as high as the others these safe windows are still abundant in conditions above the conventional operational limits. You just need the technology that indicates these windows for you.