[plbsnvgn] Pole based addressing

Instead of, or in addition to, the canonical way of specifying the address of a physical location, specifying according to latitude and longitude is helpful.

However, directly specifying the latitude and longitude is annoying because all places in a same area begin with the same prefixes.  Rather, we specify Delta differences from a nearby standardized location.  We need a set of "poles" with known standardized locations.

Because locations may be specified to arbitrary precision, we give up the notion of a unique address for a given location.  The same location may be specified many different ways depending on the pole and how the Delta is expressed.

One may establish a set of poles at cities, or one per ZIP code (the latter may be a problem if a ZIP code is split).

The Delta may be specified directly as subtracting off the pole's latitude and longitude.  It has the advantage of being able to easily transform to absolute coordinates.

The Delta may be specified in polar coordinates (angle and distance): this has the advantage that the coordinates can be made positive; the distance and angle from a pole can be easily pictured.

The distance may be specified in suitable units (meters) or in angular distance along a great circle.  The latter has the advantage that the the angle and angular distance from the North and South poles may be easily calculated given absolute latitude (90-x) and longitude (leave unchanged).

All these, of course, are very old ideas, but more relevant due to mass consumer access to GPS.