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THE DESIGN AND IMPLEMENTATION OF A MULTIPLE INSTRUMENT 
FIELD EXPERIMENT TO RELATE THE PHYSICAL PROPERTIES 
OF CROPS AND SOILS TO THEIR MULTISPECTRAL REFLECTANCE 
B.F. Robinson, M.E. Bauer, L.L. Biehl, and L.F. Silva 
Purdue University 
Laboratory for Applications of Remote Sensing 
West Lafayette, Indiana U.S.A. 
Abstract 
The design and implementation of an experiment covering three crop 
years for spring and winter wheat at three sites in the Great Plains 
region of the United States are described. The experiment involved the 
coordinated use of spectrometers mounted on mobile aerial towers, a 
helicopter-borne spectrometer, airborne multispectral scanners, and 
Landsat multispectral scanners. 
Development and use of procedures for obtaining radiometrically 
calibrated spectral measurements has permitted valid comparisons to 
be made among data acquired at different dates and times, different 
sites, and by different sensors. The data sets acquired are compre- 
hensive in terms of the number and kind of sensors, the number of 
sites and years included, the number of missions (8 to 12) for each 
year, and the amount of supporting agronomic and meteorological data 
acquired. The experimental design and the formulation of a coordinated 
data base provides opportunities for researchers to relate agronomic 
and meteorological data to the spectral data. A companion paper 
discusses the analysis and results of a portion of the data. 
Introduction 
Major advancements have been made in recent years in the capa- 
bility to acquire, process, and interpret remotely sensed multispectral 
measurements of the energy reflected and emitted from crops, soils, and 
other earth surface features. As a result of experiments such as the Large 
Area Crop Inventory Experiment (LACIE) the technology is moving rapidly 
toward operational applications [1]. There is, however, a continuing 
need for quantitative studies of the multispectral characteristics of 
crops and soils if further advancements in the technology are to be 
made. In the past, many such studies were made in the laboratory 
because of a lack of instrumentation suitable for field studies. But, 
the applicability of such studies is generally limited. The develop- 
ment of sensor systems capable of collecting high quality spectral 
measurements under field conditions has made it possible to pursue 
investigations which would not have been possible a few years ago.