1. A sensor system comprising: means for collecting data; a survivor set, said survivor set comprising survivor set members; means for generating a data set, said data set comprising data set members wherein; said means for generating compares said data set members with respective ones of said survivor set members effective to characterize said data set members as similar or dissimilar to said survivor set members according to a preselected criterion; means for including said data set members characterized as dissimilar in said survivor set; and means for generating the endmember vectors of said survivor set.