Dr. John Peterson Soil Study (801601)
Description
The purpose of this experiment was to study the relationship of soil
reflectance and soil moisture (tension). Fifty-seven samples were
selected from surface samples representing 240 representative soil
series widely distributed over the United States and supplied to
Purdue's Laboratory for Applications of Remote Sensing (LARS) by the
Soil Conservation Service (SCS). See experiment 781701. The 240
samples were selected to cover as large a range of visible spectral
properties (colors) as possible. In experiment 781701, reflectance
measurements were made of the soils equilibrated to a moisture tension of 0.1 bar. For this experiment, 57 of the 240 samples were selected to represent the range in soil charateristics known to affect reflectance such as iron oxide, organic matter content, texture, etc. Reflectance measurements of these 57 samples were made with the samples equilibrated to several other moisture tension levels . All 57 sample were run at oven dry; 12 of the 57 samples were run at 1/3 bar; 29 of the 57 were run at 15 bar; and 15 samples were run an 10 bar.
Note: The reflectance of 6 soil sample were measured on 8/12/80 at 15 bar. After that time, concern was raised that at least some of the soil samples may have not equilibrated at 15 bar moisture tension. Some of these samples were rerun on 7/17/81.