| Abstract | Raw remotely sensed satellite data have to be processed andmapped into a standard projection in order to produce a multi-
temporal data set which can then be used for regional or global
Earth science studies. However, traditional methods of
processing remotely sensed satellite data have inherent
limitations because they are based on a fixed processing chain.
Different users may need the data in different forms with
possibly different processing steps; hence, additional
transformations may have to be applied to the processed data,
resulting in potentially significant errors. In this paper, we
describe a software system, Kronos, for the generation of
custom-tailored products from the Advanced Very High
Resolution Radiometer (AVHRR) sensor. It allows the generation
of a rich set of products that can be easily specified through
a simple interface by scientists wishing to carry out Earth
system modeling or analysis. Kronos is based on a flexible
methodology and consists of four major components: ingest
and preprocessing, indexing and storage, a search and
processing engine, and a Java interface. After geo-location and
calibration, every pixel is indexed and stored using a
combination of data structures. Following the users' queries,
data are selectively retrieved and secondary processing such
as atmospheric correction, compositing, and projection are
performed as specified. The processing is divided into two
stages, the first of which involves the geo-location and
calibration of the remotely sensed data and, hence, results in
no loss of information. The second stage involves the retrieval
of the appropriate data subsets and the application of the
secondary processing specified by the user. This scheme allows
the indexing and the storage of data from different sensors
without any loss of information and, therefore, allows
assimilation of data from multiple sensors. User specified
processing can be applied later as needed.
|
