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DEFINING A KNOWLEDGE BASED SAR PROCESSOR
W. Noack
Deutsche Forschungs- und Versuchsanstalt
für Luft- und Raumfahrt
DFVLR
8031 Oberpfaffenhofen
Federal Republic of Germany
ABSTRACT
The fact that future microwave sensors like the ERS-1 Synthetic Apertur Radar
(SAR) will be operational systems, requires a processor system design which
is significantly different from existing SAR correlators. In addition more
attention must be paid to the user community needs in terms of various pro-
duct levels and adequate production and organization schemes.
This paper deals with the classification of an expert system as a part of
DFVLR's Intelligent SAR Processor (ISAR) which is identified by a distributed
architecture using a high speed array processor, enhanced by a two-dimen-
sional accessable memory, a front-end processor and a knowledge engineering
workstation. In order to ensure consistency and correctness during the
development phase an expert system will support the program designer in
accumulating the knowledge base. As a result the system will be accessible
and comprehensive for both experts and system operators.
1. INTRODUCTION
During the last years the user requirements for SAR products have been
evolving intensively. Among them are the requirements for multifrequency,
multipolarization, high radiometric and geometric precision, varying inci-
dence angles and related parameters. Furthermore a lot of experiments are
demanding multiseasonal data acquisition or the inclusion of calibration
experiments. This will result in a raised number of different products.
However, the biggest problem beside the product variety is the requirement
for high throughput together with the demand for high precision.
A simple recipy would be to speed up the correlation process employing faster
array processors based on a software oriented implementation approach.
Another possibility would be to use pure hardware boxes instead. But what
you would gain is- throughput and the processing time can easily be pushed
down below the product set up time. Moreover the hardware approach is of
disadvantage because the programming of such a system usually involves
microcoding and even nanocoding.
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