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AN AGRICULTURAL DATA BASE TO 
SUPPORT DIVERSE REMOTE SENSING APPLICATIONS 
By J. D. Murphy, G. A. May, and J. M. Downs 
USDA LACIE Project, Houston, Texas 
I. Introduction 
The Large Area Crop Inventory Experiment (LACIE) is a cooperative 
effort by the United States Department of Agriculture (USDA), the 
National Aeronautics and Space Administration (NASA), and the 
National Oceanic and Atmospheric Administration (NOAA). It is an 
experiment designed to demonstrate the applicability of remote 
sensing technology for globally monitoring wheat, an important 
world food crop. 
Experience obtained in 1975 and 1976 indicated a need to develop a 
method for reducing various variabilities within the experiment. 
Throughout the agricultural universe there are significant differences 
in land use, cultural practices, soils, and climate. These factors 
play an important role in agricultural production. A method needed 
to be developed that could capture and define the variability caused 
by these factors. 
Several approaches were considered for identifying and isolating some 
of the LACIE variability. One approach was to work at a small polit- 
ical division such as the county level, using county statistics and 
soil reports to define the variability in wheat production factors. 
This method would require detailed statistics not available for 
application in most areas outside of the United States. This amount 
of data would also create a data handling problem. Another approach 
could be to define variability at a larger division, such as a state 
or oblast, but factors affecting wheat production are geographically 
oriented and generally are independent of political and/or administra- 
tive boundaries. 
The selected approach to decreasing variability in large area estima- 
tion of agricultural crops is to treat an agricultural area as a single 
unit and divide it into subunits that 1) capture definable agronomic 
and physical parameters and associated variability that affect crop 
production, and 2) are easily manageable within the LACIE operation. 
Thus, the rationale for an agrophysical unit (APU). An APU is a 
geographical area having definable/comparable agronomic and physical 
parameters which reflect a range in agricultural use and management. 
After gaining experience with APU's, it became apparent that they 
were universally applicable as a baseline for varied analyses using 
remotely sensed data. The physical structure of these units would 
give versatility to a data base system. Thus evolved the concept 
of an automated agricultural data base using APU's. The USDA Early 
Warning and Crop Assessment Application Test unit is currently de- 
veloping such a system.