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The Wadden Sea In One Perspective

 

Mosaic of Satellite Images:

Introduction

Brockmann Consult produced a mosaic of Landsat satellite images which covers the whole trilateral Wadden Sea of Denmark, Germany and the Netherlands.

It is an example of our expertise in the production of high-quality satellite mosaics and was realized in cooperation with the Common Wadden Sea Secretariat (CWSS). The Secretariat coordinates the collaboration between the concerned countries in terms of the protection of the Wadden Sea and uses the product for public relation issues.

The composed image shows a fascinating survey over the intertidal flats of the Wadden Sea which cannot be covered by a single image with high spatial resolution.

The mosaic allows it to illustrate the entire area at low tide. Under natural conditions, always parts of the flats are covered by the tidal wave, which moves counter-clockwise through the North Sea.
The image is illustrated in true colours and displays the structures of optical-relevant water constituents, for example the distribution of suspended matter transported via river estuaries into the North Sea.

      

 
Single Landsat images from different inventory dates to compose a mosaic.

Method

The mosaic is composed of images from Landsat 7 ETM with a spatial resolution of 30x30m per pixel.

The satellite sensor detects radiation from the surface of the earth in 7 discrete bands or channels, sensitive to different wavelength ranges of the light spectrum.
In this process the spectrum of visible light is bundled in three channels, red, green and blue, which are combined into a true colour, or RGB image.

Image requirements for the mosaic where a low cloud coverage and low tide level which is seldom congruent in one image.
The selection resulted in five images acquired in a range of three years between 2001 and 2003.

Phenological differences recorded between April and July are reflected by varieties in colours (see on the right above) and had to be taken into account for the image processing.

The images have been adjusted geographically and in colour before merging.

The final Mosaic (see on the right) extends approximately 410 km from North to South and 487 km from West to East, respectively 16260 x 13647 pixels.



      



Collocation of the images after Spatial adjustment



Colour adjustment for a seamless mosaicing

Our Services

A selection of our satellite image Services:
  • Provision of mosaics or single airborne and satellite images of any requested area by our customers

  • Image processing and composition of a print of an image or mosaic subset, as designed poster or with map layout

  • Digital Data of the Wadden Sea mosaic (whole or subsets) for print-outs up to A0, exemplarily used for posters and postcards by our customers




Products derived from parts of the Mosaic composed and distributed by the National Park Authorities of Lower Saxony and Schleswig-Holstein  


   



Product derived from the Mosaic: The Wadden Sea Poster distributed by CWSS

 

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