Robert H. Beck

LARS Tech Report Number



By measuring certain physical properties of fifteen soils typical of Wisconsin-aged, glacial till soils capped with less than 60 inches of loess in Indiana, the variations in spectral response in the laboratory were explained. Spectral reflectance measure with the Exotech 20-C can be significantly explained by percent moisture, organic carbon, and clay content of these soils. The soils studied were predominantly silty with a range of organic carbon from .60 to 1.33%. The moisture content of the soils was controlled by use of the pressure membrane at 15 bars, pressure plates at 1/3 bar, and oven dried at 105°C for 24 hours in a forced air dryer. The moisture of the samples was equilibrated, and then illuminated artificially by a General Electric DXW lamp and spectrally measured from .53 µm to 2.32 µm with Exotech 20-C.

Date of this Version

January 1975