whi
It must be emphasized that evaluation of an APU approach is
not a one-time event, but a year-to-year continuing effort. pon
This aspect of the approach is, in part, what has led the des
authors to suggest maintenance of APU's via an automated ce
technique. The update mechanism must depend upon a «n
relatively unbiased data source and an efficient technique in
to apply that source. This latter criteria highlights the is
value of satellite/aircraft color infrared imagery such as eve
Landsat. The remainder of the paper will look at APU's as
input to an automated data base and their applicability via Wit
the data base to remote sensing applications. sup
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III. APU's as a Basis for Automated Data Base Design bed
dev
A. General app
The exploitation and. interpretation of remotely sensed, multispectral, B
and meteorological data rely heavily upon the utilization of automated
techniques to achieve cost efficiencies. A potential user of these
data sources has been, is, and will be faced with a classic system
design problem of attempting to achieve responsiveness to user needs,
flexibility in design, and timely throughput at the least possible
cost. In recent years, designers of information handling systems
have realized that a major contributor to design, maintenance, and
conversion costs was the application support data base(s).5 The
data base and its design is also a major contributor to the degree
a System is responsive to user needs and to the extent of flexibility
within a total system.9 The data base viewed in this context becomes
a critical design consideration when manipulating massive volumes of
multispectral, meteorological, and agricultural related data necessary
to support agricultural assessment applications which utilize remote
sensing technology. The massive data volumes coupled with changing
technology, changing user demands, and evolving technology create
an environment which can consume an inordinate amount of resources.
The USDA Remote Sensing User Requirements Task Force? and the USDA
Application Test System Design? attempted to address these problems.
Our approach to a data base concept evolved as a result of the func-
tional research and development requirements stated by the LACIE
and those of USDA management. In summary, these requirements are:
1) a common data base to support statistical sample allocation, agri-
culture/non-agriculture delineations, yield, area estimation, and
production aggregation; 2) a data base responsive to a yearly change
by management in geographic area and crops to be monitored; and 3) a
common data base to support analysis of spectral,meteorological, and
other data for varied users.
Our previous analysis and development work in defining and quantify-
ing an APU provided guidance and insight into a data base concept