Tl. Coleman et al., SPECTRAL DIFFERENTIATION OF SURFACE SOILS AND SOIL PROPERTIES - IS ITPOSSIBLE FROM SPACE PLATFORMS, Soil science, 155(4), 1993, pp. 283-293
Spectral radiance data from Landsat's Thematic Mapper (TM) sensor were
used to evaluate its effectiveness in differentiating among surface s
oils of similar properties and to identify the TM spectral band combin
ation useful in estimating selected soil properties. Correlation, regr
ession, and discriminant analyses were used in analyzing the data. The
overall accuracy of the TM sensor in differentiating the surface soil
s was 97.2%. The order of importance of the TM bands that contributed
the most in differentiating the soils was TM 6, TM 4, TM 5, TM 2, TM 7
, TM 1, and TM 3, respectively. Significant correlations were found am
ong the spectral radiance data and soil variables studied; however, th
e amount of variance explained was quite low. The prediction equation
for estimating soil properties accounted for less than 40% of the vari
ability in the data. The low percentages were attributed to atmospheri
c particles such as moisture, CO2, dust, etc. that affect the electrom
agnetic energy sensed from airborne and space platforms. It was conclu
ded that even though the TM sensor is adequate for differentiating amo
ng similar soil types from the same soil order, the spatial resolution
of the data (30 m) is still too coarse to be effectively used in gene
rating equations for predicting soil properties such as clay percentag
es, iron oxide, and organic matter content.