Taking the formulas been given by Joe1950 and translating to metrics (we need USA to go into metrics for god sake!)
L = distance in meters from the artificial star to the telescope objective
D = Objective diameter in millimeters
f = focal ratio, adimensional
n = induced error fraction denominator in the "lambda/n" induced error, Thus, Lambda /4 => n= 4; lambda/8 => n=8.
L [m] = n . (D [mm] / f ) ^2 / 302.4
D = 17.5 inches = 444.5 mm
f = 4.5
n = 8 (mean induced error of lambda/8)
L [m] = 8 . ( 444.5 / 4,5)^2 /302.4 = 8 x 9757.05 / 320.4 = 2058.12 m or 846.86 ft
Clear skies for us all!
Edited by AndresEsteban, 18 September 2020 - 08:48 PM.