A major effort was initiated in the fall of 1974 by the National
Aeronautics and Space Administration, Johnson Space Center (NASA/JSC)
with the cooperation of the U.S. Dept. of Agriculture (USDA) to acquire
fully annotated and calibrated multitemporal sets of spectral measure-
ments and supporting agronomic and meteorological data [2]. The Purdue
University, Laboratory for Applications of Remote Sensing (Purdue/LARS)
was responsible for the technical design and coordination of the exper-
iment.
Spectral, agronomic, and meteorological measurements were made at
three LACIE test sites in Kansas, South Dakota, and North Dakota for
three years. The remote sensing measurements include data acquired
by truck-mounted spectrometers, a helicopter-borne spectrometer, air-
borne multispectral scanners, and the Landsat multispectral scanners.
These data are supplemented by an extensive set of agronomic and
meteorological data acquired during each mission.
The LACIE Field Measurements data form one of the most complete
and best documented data sets acquired for agricultural remote sensing
research [3]. Thus, they are well-suited to serve as a data base for
research to (1) quantitatively determine the relationship of spectral
to agronomic characteristics of crops, (2) define future sensor systems,
and (3) develop advanced data analysis techniques. The data base is
unique in its comprehensiveness of sensors and missions over the same
sites throughout the growing season and the calibration of all multi-
spectral data to a common standard.
Experimental Approach and Rationale
Spectral, agronomic, and meteorological measurements for the
field measurements project were made at three LACIE test sites during
the 1975, 1976 and 1977 crop years. The sites are in Finney County,
Kansas; Williams County, North Dakota; and Hand County, South Dakota
(Figure 1). Finney and Williams Counties were chosen to represent
winter and spring wheat growing areas, respectively. Both winter and
spring wheat are grown in Hand County. Data were collected at the
sites for three years to obtain a measure of the year to year variation
in growing conditions and their influence on spectral response.
The primary sensors were truck-mounted spectrometers, a helicopter-
borne spectrometer, an aircraft multispectral scanner, and Landsat-2
multispectral scanner. Each sensor system has unique capabilities for
acquiring spectral data. The spectrometer systems produce the highest
quality reflectance measurements, but provide only limited measurements
of spatial variability. On the other hand, an aircraft scanner provides
spatial sampling of the scene and can obtain data at multiple altitudes,
but its spectral coverage is limited to a fixed set of wavelength bands.
The helicopter and aircraft data acquisition systems have the advantage
of flexible scheduling and, therefore, provide greater opportunity to
obtain cloud-free data at critical crop growth stages than the Landsat