Background and objectives
The Swedish Maritime Administration (SMA) distributes official nautical charts and publications in Swedish waters. A large effort is made to collect all necessary information within a specific area. SMA is working continously with hydrographic survey, primarily in fairways, and with positioning of objects that are of importance for navigation. Different methods and techniques are used to collect the information, with focus on multi beam technique. Remote sensing is one of the techniques that only has been used to a very limited extent so far, but that has the potential to be a better alternative to some of the exisiting techniques and improve the contents of the nautical charts. Especially in more shallow areas, were the accessibility of ship based information collection is very limited. The general purpose of this project is to evaluate the possibility of using high resolution satellite data to collect information about a number of objects of interest and to clearly describe the advantages and disadvantages of using this technique compared to ones presently used at SMA.
The developments and classifications during 2007 will be based on existing QuickBird images collected within Municipality of Norrköping during 2006 and new image acquisitions during 2007. The main focus will be on the panchromatic data with respect to the higher resolution, but the multispectral data will most likely be very important in several steps of the development. Based on the satellite data, information from the nautical charts and available NSL data, image analysis will be performed in order to evaluate if this type of imagery can be used to map (size and location) small islets and rocks in the Swedish archipelago, if rocks located under the surface also can be mapped and an estimation of maximum depth, to what extent beacons and navigational marks can be identified in the images and if the geometric accuracy of the image is enough for SMA’s purposes, and, finally, to make a comparison between the existing shoreline, based on aerial photo interpretations, and the shoreline that could be mapped from high resolution satellite imagery.
In addition to the object detection developments, the production advantages and disadvantages of using satellite data compared to other techniues will also be investigated and clearly defined, i.e. cost, reliability, object identification, flexibility (area, season), accessibility to data, possibility to automate the detection process and the possibility to obtain updated information.
Some of the objectives of this study, e.g. the comparison between NSL and the shoreline that can be obtained from high resolution satellite imagery, are included to increace the knowledge about the existing shoreline and its descrepancies from the specifications. There is no plan, as of today, to change the existing shore line, but the results can serve as a good basis for future discussions.
With respect to the other objects the developed methods will be implemented in the hydrograpic production line during 2008+ at SMA, if they are evaluated to be useful and cost effective alternatives and/or complement to the existing information collection techniques. If there are any economical benefits to be made with respect to the existing techniques, will be evaluated during the project. It is equally important though, to develop methods that can retrieve information that are missing in the existing database.
Vattenfall Power Consultant AB:
Petra Philipson, 08-739 59 33, petra.philipson(a)vattenfall.com
Swedish Maritime Administration:
Lars Jakobsson, 011-191093, lars.jakobsson(a)sjofartsverket.se