The Darcie–Whalen reflection method is ambiguous and has a chart area of 72%, which is less sensitive than method H—Owen's classification—which is unambiguous and has a chart area of 100%.
© 1996 Optical Society of America
P. C. Logofaˇtu, D. Apostol, V. Damian, and R. Tumbar, "Ambiguities in determining the optical constants for two reflection methods," Appl. Opt. 35, 117-119 (1996)