The Fuller projection is simply an icosahedral framework with vertices at the poles - i.e., Zero, 72, 144, 216, 288 degrees of longitude extend to 60 latitude to define the northern Major Triad "ring".
The latitude output of my old but trusty Etrex Venture selects a narrower ring of triangles from a lookup table. The width of the ring depends on the precision of the measurement. The longitude output selects the specific triangle within the ring. Does this help? There's more on the method for designating interior subdivisions that creates a longitudinal component for fast lookup. - Brian Will King wrote: > Hello Brian > > Couple of questions. How are you converting/planning to convert > between wgs84 lat long and Fuller's projection? What gps are you > currently/thinking about using? > > > > > > On 7/4/08, Brian Grant <[EMAIL PROTECTED]> wrote: >> as a pragmatic exercise allow me to start with a map and end with a >> database schema. >> >> 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 >> Major Triad. >> >> 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 >> through TT. >> >> 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. >> >> - Brian >> >> >> >> >> >> >> _______________________________________________ >> Geowanking mailing list >> [email protected] >> http://lists.burri.to/mailman/listinfo/geowanking >> > > > ------------------------------------------------------------------------ > > > No virus found in this incoming message. > Checked by AVG. > Version: 8.0.134 / Virus Database: 270.4.5/1533 - Release Date: 7/3/2008 7:19 > PM _______________________________________________ Geowanking mailing list [email protected] http://lists.burri.to/mailman/listinfo/geowanking
