I have the two points in
A: 520474.065771355,7146471.63532946 B: 523398.322298721,7146491.17961279,1056.79350172838 Distance A-B: 2925.739824m
When I convert them to
NAD_1983_UTM_Zone_10N I get the points:
A: -54764.4762031343,7197193.19405588 B: -51878.0632641406,7196659.83388472 Distance A-B: 2936.689978m
Both coordinate systems are using the same spheroid and datum. What is causing the 11m discrepancy between the A-B distances?
In UTM projection, distortion is small near central meridian, when you move away it increases.
B are near central meridian in
UTM Zone 8. When you convert them to
UTM Zone 10, coordinates of
B are calculated based on in
UTM Zone 10.
After converting, points are in the same location on earth, but far from central meridian of
Zone 10 in comparison with
Zone 8's. Therefore, distortion of
A-B distance is more. This is nature of UTM.