Other Geometries

Some specific geometrical constructs are used in the design of instrument approach/departure procedures and in the design of route segments in the AI domain. They are mentioned in this section for completeness sake. More details about their encoding in GML might be provided in a future version of  the coding guidelines. The first one is the “wind spiral”, as represented in Figure below:

Other such geometrical constructs are the “segment locus” and “arc locus” (see figures below):

Arc locus is the non-flat generalization of Archimedean spiral. An arc locus is a set of points whose (geodesic) distance from a given defining geodesic circle is a linearly varying function of the length parameter on the circle, of the point projection.