bul 2004 International Archives of the Photogrammetry, Remote Sensing and Spatial I nformation Sciences, Vol XXX V, Part B4. Istanbul 2004 
The model also includes transformations to the required map 
projection in the request. The full set of EPSG namespace 
id image | projection codes are supported, in addition to the OGC 
| specified AUTO namespace projections. 
5,2 Orthorectification 
  
  
onstruct a The geometric relationships in the sensor model are used to 
viewing control the rectification of the browse to the required output 
necessary map frame. Before the rectification, the browses are stripped 
orbits and from non-image areas, such as decorative frames, During 
tored in a rectification, nodata areas are handled, to eventually be made 
transparent or background coloured. The rectification projects : : ; ; 
2, the image to the ellipsoid or to the DEM (orthorectification), Figure 7. One single AATSR browse image covering a 
A depending on the style set in the request. Orthorectification can COMplete orbits revolution, rectified to the Plate-Carrée 
be of great importance, especially for SAR images, even at the projection. 
| small scale of browse images (Figure 6). 
by | 
5.3 Mosaic 
| | All rectified browse images are merged in a mosaic. The 
x, method of blending in overlap areas can be selected by a special 
vendor specific tag in the GetMap request. The possible 
selectable blending modes in the request are: 
ECI 
|. Most recent pixel 
2. Closest to centre of time interval 
3. Pixel average 
4. Pixel of lowest luminance 
| space 
| the browse 
versa. The 
ise a global 
quired. The 
  
purpose. 
Figure 8 Two weeks of AATSR acquisitions mosaic, using the 
most recent pixel blending option 
m WMS 
respons 
  
Figure 6 Orthorectified ASAR image over India and Nepal 
A special challenge was how to make possible the rectification 
of images with such a large degree of variation in layout as 
browses from the MUIS catalogue. The browses represents all 
from a few swath's, up to a full orbit's acquisition. T& handle 
  
an image representing a whole orbit, passing the datum line, Figure 9 Two weeks of AATSR acquisitions mosaic, using the 
and biting itself in the tail, required the development of special pixel of lowest luminance blending option 
rectification algorithms (Figure 7). > 
1159