This issue’s theme is 'Underwater Imaging'. Underwater imaging has a broad aspect and includes optical and acoustic imaging as well as other types such as electrical and thermal imaging. This issue deals only with acoustic, magnetic and optical imaging.
For a variety of reasons, images of underwater objects are not as sharp as those made above water. This also affects the ability to accurately chart underwater features. Although enormous progress has been made over recent decades it is unlikely that we will completely overcome the differences presented by the media of air and water. But UUVs can bring our instruments close to the objects we want to inspect and give useful results, as shown by the article on the HMS Arc Royal which illustrates how acoustic, as well as optical imaging can render a good impression of what you are looking at. There are also some good video examples of acoustic imaging on www.soundmetrics.com.
As security becomes increasingly prominent and underwater structures increase in number, underwater imaging will grow in usage. Examples of this include renewable energy installations like windmill farms, with their scouring effects (there are prospects for over 15,000 turbines) and tidal energy installations that also require periodic inspections. Multi-beam systems provide us with more and more data. However, in order to be useful these enormous datasets are best evaluated by advanced imaging software and evaluation may even be necessary by, for example, acoustic imaging. Imaging
data collected digitally is far easier to use in 3D modelling of imaged objects to give a virtual underwater picture.
We know our Product Surveys are well appreciated by our readership. We like to have these surveys as complete as possible and try to reach all relevant manufacturers. However, we also expect manufacturers to make themselves known to us. One good way of doing this is by making sure that your company participates in the service designated www.ocean-source.com. This website is the digital, online successor to the paper-orientated ‘Sourcebook’ formerly distributed yearly to all Hydro international readers and listing companies active in the hydrographic business. Although the sourcebook was well appreciated by our readers, we felt the time was ripe for a more efficient and user-friendly successor to supply you with information. One of the sources for manufacturers and/or service providers for our Product Surveys is, of course, our own ‘on line digital sourcebook’. So make sure that your company details are registered there. For more information on how to participate visit www.ocean-source.com.
Talking about websites that provide easy access to a business sector, http://gis.nitle.org/literature.php gives information and links on GIS. To my surprise, there is hardly any information on GIS about in our profession. Either we are underdeveloped in this area or we need to do more on our public relations.
Finally, the feature 'Marine 3D Full Tensor Gravity Gradiometry' by Gary Mumaw submitted in time for our July/August-issue (theme ‘Magnetometry and Gradiometry’) showed that we as an editorial board were too focused on magnetic gradiometry and not fully enough aware of the innovations in technology and the increasingly widespread utility of gravity gradiometry. Since many of our readers are interested in this technique we have this month specially reserved a place for this feature, which we were unable to publish in our previous issue due to lack of space.