This classification was developed from broad band spectra (between 0.31 μm and 1.06 μm) obtained during the Eight-Color Asteroid Survey (ECAS) in the 1980s, in combination with albedo measurements.
Detta klassifikationsystem utvecklades från mätningar av bredbandsspektra (mellan 0,31μm och 1,06μm) som erhölls under Eight-Color Asteroid Survey (ECAS) på 1980-talet, i kombiantion med albedomätningar.