I have created lines between multiple points that are across MGA 54 and 55S (EPSG 28355). I am trying to calculate the distance between points but different methods give different answers (~1km difference).
All data is in GDA94 (EPSG 4283 as it en composes both projections)
If anyone wants to try the two test points are
Normanton PO -17.669563 141.079541 to Mareeba site (off Kirrakoppa Rd) 145.417391 -16.999263
What is the most accurate method? if any.
Source question for background is Draw line between points from multiple datasets
Answer
Presuming your original coordinates are indeed where you hope to start and finish in the real world, the correct distance is 467009.0 metres in UTM. No doubt QLD Albers is better, but will whoever uses the data after you be working with that precision / technology?
If you pay for a road gang to lay tarmac the full distance, they may engage a surveyor to check that there is 468 km or less in that distance. They may still try to charge you for the GDA94 distance....
When a new model for the Geodesy of that part of the world is released a few years into the future, they may argue that they didn't get paid enough.
So what version of the distance you accept is a point of arbitrage, depending on your purpose.
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