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Education/Training
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Remote Sensing Data Servers: An Enabling Technology for the development of Applications
4-Enabling Tools: The Remote Sensing Data Server
4-1- Objectives
A common requirement to the above discussed application domains is the Remote Sensing Data Server. Elaborating on the development of such a server with partners like the EU Joint Research Center, SPOT Image, ESA/ESRIN… the ISIS enabling tool can be proposed:
- User Defined Formats are pre-selected and limited in number to allow the delivery of the adequate format to the desktop.
- GIS Information is provided in support to satellite image data to to answer to applications requiring also geographical information.
- Accounting schemes are demonstrated which can take into consideration ythe actual amount of data retrieved, other application specific parameters, e.g. the use of a particular algorithm, and reflect resource consumption, e.g. processing time.
- Application Specific Service Interaction. The ISIS server interaction and users interfaces are tailored to the different applications, e.g. a sea-surface temperature processing in support to fishery in Ireland will display a corresponding map of the costal zone and use pre-selected algorithms and data sets from a priori identified suitable sensors.
- Intranets-internet/Euro-ISDN. ISIS demonstrates how both private and public data networks, can be used to improve delivery times. Data centers may be connected through Intranets, whereas users may make use of Internet/Euro-ISDN to connect to data centers.
- Internet technologies are the basis for the system. They provide development-facto standards and a large market of commercial products, providing interoperability and scalability. Millions of people are used to the look and feel of the World Wide Web services and the WWW will support the wide adoption of Java based user interfaces and functions.
- Transport Client Software Configuration allows the client software to be delivered to the user automatically through the internet so the inconvenience of additional software installation is avoided.
- Tool Kits for client interface creation and server functions implementation make it relatively easy for organizations to create new application oriented user interfaces and applications. The same technique will be applied to the server to introduce nesting site processing functions.
- Object Request Broker technology is the basis of the system architecture, allowing a modern, modular, object oriented design and the distribution of functions across networks. ISIS will use technologies based upon COBRA, the common objects request broker architecture standard.
4.2 - Selective Compression
Intelligent Data Selection and Compression [1,2] provides a set of techniques to select the information of interest, e.g. geographical area, and reduce the amount of data transmitted over networks. By extracting only the region of an Earth Observation product a user needs, processing it to only the information needed by the application, and subsequently compressing the data, the volume will be greatly reduced [3].
"Regions off Interest" definitions will allow the users to define arbitrary geographical areas independently of the coverage of the product that was acquired by the satellite.
Figure 2: Intelligent Selection & compression
Figure 3: Example
References
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M. Carisohn, M. Paillou, M. Louys, F. Bonnarel, Evaluation of Codings of Space Images with respect to their Astronomical Semantics, Proc. $th Int. Workshop on Image Analysis and Synthesis, 1993
- H. LI, A. Lundmark, R. Forchheimer, Image Sequence Coding at Very Low Bitrates : a Review, IEEE Image Processing, precursors 1057-1149, 1994
- VD. Vaugan, T. Wilkinson, System Considerations for Multispectral Image Compression Designers, IEEE Signal Processing Magazine, precursors. 1053-1088, 1995.
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