[Geowanking] pragmatic exercise
hbgrant at voyager.net
Fri Jul 4 07:17:23 PDT 2008
as a pragmatic exercise allow me to start with a map and end with a
begin with a Fuller projection
(http://en.wikipedia.org/wiki/Fuller_projection) an icosahedral
framework of 20 triangular areas (actually tetrahedra to the center -
but we'll leave that out for now). Each triangular area is designated a
Each Major Triad is subdivided ** by the same base as the original
sphere ** into 400 Minor Triads (20^2). If the edge of a Major Triad is
8,000 km the edges of the Minor Triads are 400 km. Major Triads are
designated with characters A through T; Minor Triads are designated AA
Minor Triads are further subdivided into Trixels (or whatever) again by
the same base creating a recursive triangular mesh capable of defining
unique triangular regions 2.5 m on edge with 13 characters.
Forgive me as it may be apparent by now that I'm not a geographer. I'm
an application engineer that builds wireless sensor networks and needs a
place to store data based on sensor location - sometimes static -
sometimes mobile. I've got networks in the US, Pacific islands, India
and Europe. This Recursive Triangular Mesh is what I'm using to do it.
The database schema is nothing more than a wiki with a directory
structure that looks like "D/FH/KP/ET/SA/RO" - addressing a unique area
of less than 3 square meters directly converted from a Lat/Long point.
My other concern is the precision and accuracy of the location measuring
instrument - how many digits does my GPS provide? It defines the size of
the final Trixel.
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