Purdue Agronomy Farm Instrument Altitude (791811)
The object of the experiment is to determine how the canopy
reflectance varies as a function of height above the crop and,
particularly, what minimum height is needed to acquire repeatable
reflectance measurements. Data were acquired on three canopies,
mature corn planted in 76 cm rows (field 52) mature soybeans
planted in 96 cm rows with 50 to 70% ground cover (field 898) and
mature soybeans planted in 76 cm rows with 100% ground cover
(field 899). The canopies provided scenes with a range of row effects
from pronounced rows to no obvious rows. Data were acquired at 10
heights hanging from 0.5m to 10m above the canopy. At each height
12 reflectance data points were acquired at 15 cm intervals in the
direction perpendicular to the rows by moving the spectrometer
along a horizontal board. The data analysis involves determining how
the variance of the data obtained at each height changes with height.
This analysis will provide the information necessary to place error
bounds on reflectance data acquired at a particular height.
Other Notes