Loxodrome Creator

From fmepedia

This page contains a Custom Transformer created by an fmepedia user.   See the attached files list at the foot of this page for the zip file containing this custom transformer.

Here's the output from a new custom transformer from Safe's Dmitri Bagh...

This output is a rhumbline - also known as a loxodrome (http://en.wikipedia.org/wiki/Loxodrome).

A loxodrome is a line of constant bearing on a map, i.e. the bearing to follow that line remains constant as you travel along it. They look similar to a great circle (http://en.wikipedia.org/wiki/Great_circle), but a great circle is a line of constantly changing bearing, i.e. the bearing to follow a great circle changes as you travel along it. On the above image the rhumb line looks like a curve - well it is a curve, but one of constant bearing to north because the lines of longitude are splayed out in different directions. On a Mercator projection (http://en.wikipedia.org/wiki/Mercator_projection) it would appear as a straight line (because the lines of longitude on a Mercator map all run in the same up-down direction).

Loxodromes are preferred for navigation purposes because they enable you to steer a straight line, albeit one that isn't the exact shortest route. As I understand it, airlines navigate by cutting a great circle route into a number of shorter rhumblines - as to follow a great circle would mean the aircraft constantly banking!

The custom transformer used to create this output was developed for a customer as part of Safe's Solutions Assistance (http://www.safe.com/services/solution-assistance/index.php) program, so, unfortunately, we aren't able to share it with you at this time.

Got a good workspace? ...or custom transformer, custom format etc? Send it to fmepedia@safe.com (mailto:fmepedia@safe.com) and let us share it with the FME world.