On January 18th, 2016 a new and cool satellite was launched into space.
The Jason-3 carries an array of oceanographic sensors that are capable of measuring sea level heights, currents and even capturing information on wind speed.
What excites me most though is its ability to measure sea level heights to within 3.3cm – globally. Will this ability and order or accuracy make our traditional seabed mounted tide gauges obsolete?
Why does this excite me?
Not because I don’t like tide gauges, but tides are the largest source of error in an offshore hydrographic surveying and the more we know about them the more accurate our charts can become. The Jason-3 suite of sensors should provide valuable data to help improve our understanding and modelling of tides worldwide, thereby making charts more accurate for the mariner.
There are thousands of offshore shoals and banks that pose a hazard to shipping. Charting them to a high order of accuracy requires accurate tide data and this traditionally requires us to install seabed mounted tide gauges or as is more common now, to use satellited derived tides and models, but in doing so accepting a greater source of tide error. Installing seabed mounted gauges is a costly and time consuming operation that that requires people and vessels to be on-site installing equipment often for days. The use of GNSS tides, or satellite derived tide data, which requires no on-site equipment is often the preference so that the survey vessels can collect more bathymetric data for the same amount of money.
Whilst this approach is certainly supported, the advances in technology and accuracies quoted by the Jason-3 satellite will eventually mean there is no compromise. By potentially providing this critical tide or sea level link, it is paving the way for high accuracy hydrographic surveys to be conducted without people even being on site through the use of autonomous vessels - but that’s another topic.
The future of tide gauges
In my opinion, even with the advances in technology and accuracy such as demonstrated here, the use of satellite derived tides will remain an option in the less complex offshore regions only. Tide gauges will remain the tool of choice in the more challenging coastal regions where topography has a greater impact.
I am looking forward to following the Jason-3's progress and how it contributes to hydrography.
Check out this really interesting article with more information on the Jason-3 satellite.Meet Jason-3
Related Tag: Geophysical Survey Company