Hydrographic surveying has evolved in the last 20 years. Different revolutions in ocean mapping technologies have made new ocean mapping applications possible.
Positioning
Most positioning at the sea is done using GPS. This routinely supplies cheap, consistent, accurate positions, globally referenced, easily accessible and accurate positions to the largest tanker and smallest pleasure boat.
In most cases, GPS positional uncertainty is smaller than the uncertainties in the existing nautical charts and ocean maps. When nautical charts are replaced with ones that are compatible with GPS uncertainties, having smaller uncertainties, it becomes a big challenge that some electronic charts advocates argue is not worth undertaking.
Promote sensing information
Airborne images and satellite technologies have revolutionized ocean mapping in different ways. Features of the ocean surface as small as few centimetres in height and altimetry from satellites maps changes in. such information can be used to track El Nino changes and to reveal the existence of undersea topography during hydrographic surveying Australia. Undersea topography has a gravitational pull that causes the surface of the sea to deflect.
Dynamic behaviour of the ocean information and information about climate and weather can also be extracted. Another remote sensing technology shows small variations in the temperature of the surface of the ocean. Since certain types of fish and their food chains thrive with low-temperature ranges, the maps are beneficial indicators of where the species can be found.
Digital products
Most of hydrographic surveying, cartography and charting have undergone a revolution over the past two decades. They have become an information technology. Geomatics is the name given to these computer-assisted mapping activities and surveying collectively.
One consequence is that hydrographic charts and ocean maps are evolving from analogue products to digital products. The transition will take time but it will eventually take place and digital mapping products will be used by customers who have no intention of using them for navigation.