If the bands that were used to create the statistics for the signature file are different from the bands used in the classification, inconsistent results will occur. In this case, the number of parametric bands is not the same in the signature file and the input rasters or bands in the stack. Parametric bands usually represent continuous phenomena such as elevation, color of light, or distance from a feature. Nonparametric bands usually represent discrete objects such as houses, roads, or rivers.
The signature file is created from training samples in a supervised classification or specified statistical groupings in an unsupervised classification. The signature file defines the statistics for each class that will be used in the classification. The same rasters or Grid stack that were used to create the signature file should be input into maximum likelihood or class probability to perform the classification.
Make sure that the same input bands that were used to create the signature file are used in subsequent multivariate tools.