Also near the poles the latitude/longitude grid is highly non-linear, and several errors may occur in calculations that are sufficiently accurate on other locations.
An example of the consequences of omitting such code is the crash of the navigation systems of twelve F-22 Raptor fighter aircraft while crossing this meridian.
When carrying out several calculations within a limited area, a Cartesian coordinate system might be defined with the origin at a specified Earth-fixed position.
The axes are typically selected as North-East-Down or East-North-Up, and thus this system can be viewed as a linearization of the meridians and parallels.
Instead of one local Cartesian grid, that needs to be repositioned as the position of interest moves, a fixed set of map projections covering the Earth can be defined.
UTM is one such system, dividing the Earth into 60 longitude zones (and with UPS covering the Polar regions).