Latitude and Longitude are references ultimately based on astronomical phenomena. The Latitude is based on the angle of the North Star in the sky (for the NH) and Longitude is related to clocks and time zones. You might know your Lat/Lon coordinate point, but this would do nothing to show the distance between those points. This is how GPS, and formally the land-based LORAN, operate. The station knows its own coordinates and it is giving you your own coordinates based on triangulation.
Incorrect, as you are wont to say.
GPS uses trilateration, not triangulation.
https://gisgeography.com/trilateration-triangulation-gps/You have agreed GPS can tell you your longitude and latitude. But mapping applications can use that information to accurately plot routes between one set of co-ordinates and another. How can it do that if it doesn't know the distance between them? And while we are here, the distance between degrees of Longitude is highest at the equator and gets smaller the further north
or south you go. But on the monopole FE map the distance would have to keep getting bigger and bigger the further south you are. Some simple testing in Australia would immediately show that to be incorrect.
Much of professional GPS and GIS work, by the way, assumes that the earth is flat.
So? This is like your somewhat dishonest quoting elsewhere in the Wiki of some aerodynamics manual which talks about a flat earth. But it does so listing it as a
simplification. It also lists as another simplification the airplane being of constant mass - which it won't be of course as it is constantly using fuel. So yes, sometimes simplifications are used but the very fact they're acknowledged as simplifications shows that they do not match the reality. In fact, the part you quoted
says: "the
fiction that the earth is flat, which, of course, immediately introduces distortion"
And the very next sentence, which you didn't quote, says "it is worthwhile to spend some time discussing how the distortions are handled". A paragraph or two later it says:
As long as the extent of the coverage of the coordinate system is limited, the curvature aspect—while it leads to distortion—can be managed. It's when the flat map, the flat coordinate system, extends beyond a limited area that the distortion can get out of hand. Therefore, the projection of points from the Earth’s surface onto a reference ellipsoid and finally onto flat maps is still viable.
And on map projections it says:
State Plane Coordinate Systems are built on map projections. Map projection means representing a portion of the actual Earth on a plane. Done for hundreds of years to create paper maps, it continues, but map projection today is most often really a mathematical procedure done in a computer. Nevertheless, even in an electronic world, it cannot be done without distortion.
In fact much of the article
you posted is discussing the problem of projection from the surface of an ellipsoid earth on to a plane. Why is any of that necessary? If the earth is flat then no projection is required. But in reality it is. Why?