Each navigation light system must meet the following:
Ie = G/(0.2 + t2-t1)
Where
Ie = Luminous Intensity.
G = Integral of Idt evaluated between the limits of t1 and t2.
t1 = Time in seconds of the beginning of the flash.
t2 = Time in seconds of the end of the flash.
I = Instantaneous intensity during the flash.
46 C.F.R. §111.75-17
The limits, t1 and t2, are to be chosen so as to maximize Ie.