Dr. Alan Harris' (JPL) famous Fourier Analysis method, FALC, is a de facto standard for asteroid light curve period analysis1. Dr. Harris is one of the most recognized leaders in asteroid research. He developed a program called Fourier Analysis of Light Curves FALC, that takes multiple light curve segments (ObsSets) and performs a Fourier analysis on the data. For each light curve segment, a new magnitude level (zero-point) is assumed. It is also possible to do a linear least squares fit for a specified period up to any harmonic order.

Dr. Harris' method is fully integrated in Peranso, through the FALC Period Determination dialog box, which is described in Tutorial 7. In addition, Peranso provides a FALC (Harris) Workbench, that presents Dr. Harris' method in a convenient graphical user interface (GUI). This GUI is extremely useful for asteroid enthusiasts, and mimics FALCs original approach in a Windows environment. The FALC Workbench also provides sophisticated outputs, showing f.i. the uncertainty of the fitted curve. In addition, it allows to keep a period constant and increment harmonic orders, to determine the most significant fit order to work with.

Dr. Harris' method is very interesting too for variable star light curve analysis, as it effectively takes into account brightness error values in the period determination. FALC and Generalized Lomb-Scargle currently are the only methods in Peranso that use the error bar (sigma) of magnitudes.

A full introduction to the FALC method is provided in Tutorial 7. Prominent periods of the Period Window appear as valleys. 

(1) Harris, A.W., Young, J.W., Bowell, E., Martin, L.J., Millis, R.L., Poutanen, M., Scaltriti, F., Zappala, V., Schober, H.J., Debehogne, H., Zeigler, K.: 1989, Icarus 77, 171-186.