d 2+ (ht-hr)2 = 1,000,784.
Taking the square root gives the length: 1000.3919 meter
d 2+ (ht-hr)2 = 1,001,024.
Taking the square root gives the length: 1000.5119 meter
1000.5119 meter - 1000.3919 meter = 0.12 meter
At a wavelength l = c / f = 0.3 meter,
this phase difference corresponds to 0.4 l, or 144 degrees.
For large propagation ranges, i.e., for large d, one finds the approximate expression
,
This is 2p/l times 0.12 meter.
How significant is the difference?
The approximation is quite accurate.
