International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B4. Istanbul 2004 In
1. The WMS communication interface 5. GEOSERVER MODULE | Tt
2. The geoserver module for rectification and | pr
mosiacking The geoserver module handles all the metadata and image pr
3. The catalogue communication interface. processing tasks. sp:
The geoserver module is designed to handle all concurrency — 9.1. Sensor models 57
issues and is also responsible for issues such as scalability and ; : ;
fault tolerance. At an carly stage it was decided to try The metadata retrieved for a browse is used to reconstruct a Th
application server technology, in particular JBoss. This rigorous photogrammetric model for the image viewing col
approach was successful and the design of the system could geometry (Figure 5). To be able to achieve this, i is necessaty ma
benefit from qualities of the JBoss application server such as 10 also Know nominal parameters for the satellite orbits and fro
fault tolerance, scalability and load balancing. The application instruments involved for each browse. This data is stored ina rec
server technology is a proven technology and it S now shown" ^ configuration file. trai
that it also works with massive parallel image processing. The the
selected JBoss solution makes it possible to scale the system der
be
from a single computer to many computers working in a cluster.
The main functionality of the WMS Image Server can be
summarised in the following steps
1. Parse the WMS client request.
2. Compile and send an inventory retrieve search in
MUIS for browse metadata that fit the request.
3. Filter and process the retrieved metadata.
4. Send requests to MUIS for all browse images needed
for the requested map.
5. Construct a rigorous geometric model for each
browse image.
6. Rectify each browse image to the required map
projection.
7. Merge all rectified images in a mosaic, using the i : $i eat nites:
iE : T Minn Figure 5 Rigorous acquisition model build in inertial space
required blending modes and layer priorities, and
code it to the required image file format.
8. Compile the WMS map response and dispatch it to The model is used to transform image coordinates in the browse
the WMS client. image to the ground coordinate system, and vice versa. The
rigorous 3D viewing model makes it possible to use a global
All processing is performed on-the-fly. Figure 4 illustrates the — DEM to make true orthocorrection possible if required. The
parallel process flow design. GLOBE 30' DEM is available on the server for this purpose.
Request Metadata Sensor Ortho- Layer Image Layer
proc proc models rectification mosalcs enhance merge
LT TX Ou TETE jid
layer |__| (MIAGE, image i2» layer layer N
— ial ve van
nage]. — image
N
:
/ magi]
Rs t rr d — WHS
WHS gl | map K layer |<H M sh | ayer | map | B espons
aa} | /
request
image} + - [image ]--...
layer Fr [image image]-,— E» laver 7T]
re asset x
image image o
A Figur
Inventory Browse A spe
parameters Metadata | DEM images X
of im
| brows
from.
an im
and bi
réctifi
Figure 4. The WMS Image Server process flow
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