Depth estimations and mapping of maritime objects

High resolution satellite data for depth estimations and mapping of maritime objects

Background

 
The Swedish Maritime Administration (SMA) distributes official nautical charts and publications in Swedish waters and different methods and techniques are used to collect the relevant data. Remote sensing is one of the techniques that has only been used to a very limited extent so far but that has the potential, especially in shallow areas, of improving the contents of nautical charts.

 

Goal

 

The general purpose of this project is to evaluate the possibility of using high resolution satellite data to collect information about a number of nautical objects and, to investigate to what extent the information collection process could be automated, to develop a strategy to include the satellite data in the existing nautical database at SMA and to test the developed strategy in a pilot production. Additionally, a more exhaustive analysis regarding the possibility to estimate depth from high-resolution optical satellites will be performed.

 

Approach

 
The investigations have, and will be, based on two QuickBird images collected in the county of Östergötland, east of Arkö-Gränsö during 2006, one over the archipelago southeast of Nämdö, Stockholm in 2002 and new image acquisitions during 08/09. QuickBird generates images with a spatial resolution of 0.6 m in panchromatic mode (“black and white”) and 2.4 m in multispectral mode (blue, green, red and near infrared).

Based on satellite data, information from nautical charts, NSL data and depth data based on LASER measurements, image analysis has been performed in order to evaluate 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.

The main part of the method developments regarding maritime objects was performed during 2007. The work during the end of 2007 has been dedicated to evaluation of the results, together with the end user, to identify to what extent high-resolution satellite data could be an alternative source of nautical information for SMA. During 2008 and 2009 we will continue the work with further development of the methods, based on the evaluation in the end of 2007, investigate to what extent the information collection process could be automated, develop a strategy to include the satellite data in the existing nautical database at SMA and test the developed strategy in a “pilot production”.
Additionally, during 2008-2009 we will extend the project with a more exhaustive analysis regarding the possibility to estimate depth from high-resolution optical satellites.
 

Contacts

 
Vattenfall Power Consultant AB: Petra Philipson, 08-739 59 33, petra.philipson@vattenfall.com

Swedish Maritime Administration: Lars Jakobsson, 011-191093, lars.jakobsson@sjofartsverket.se

 

Senast uppdaterad: 20 maj 2009