Three PCA bands were created using prescriptions from a Principle Components 
Analysis (PCA). These three bands were used as the R/G/B components in the 
HSV (also known as Hue Saturation Intensity (HSI)) process in ENVI. The value 
(intensity) component of the RGB image was replaced with the 10m SPOT 
panchromatic imagery for the study area. The resulting RGB was split back into 
the three PCA components in its 10m form. pca10m_final.gis is the final 
product resulting from the weighted expression for the three components 
of the PCA that combined the three PCA bands.