Along parallels, each point from the surface is mapped at a distance from the central meridian that is proportional to its difference in longitude from the central meridian.
32.
With no distortion along the central meridian and the equator, distances along those lines are correct, as are the angles of intersection of other lines with those two lines.
33.
Ptolemy of Alexandria mapped the stars in Book VII and VIII of his " Almagest ", in which he used Sirius as the location for the globe's central meridian.
34.
Ptolemy of Alexandria mapped the stars in Books VII and VIII of his " Almagest ", in which he used Sirius as the location for the globe's central meridian.
35.
In the first equation " ? " 0 is the longitude of an arbitrary central meridian usually, but not always, that of Greenwich ( i . e ., zero ).
36.
Since the central meridian of the transverse Mercator can be chosen at will, it may be used to construct highly accurate maps ( of narrow width ) anywhere on the globe.
37.
This is not always the Earth's prime meridian ( 0?W / 0?E ), as the central meridian of the Earth as seen from the Moon changes as the Earth rotates.
38.
The direct series are developed in terms of the longitude difference from the central meridian, expressed in radians : the inverse series are developed in terms of the ratio x / a.
39.
However, there is no motion for this at the moment, and the accuracy of the projection would start to diminish in the west of Ireland, more than 8 degrees from the central meridian.
40.
It is the transverse aspect of the equirectangular projection, in that the globe is first rotated so the central meridian becomes the " equator ", and then the normal equirectangular projection is applied.
