Andy Ross writes: > > Using the Toms algorithm would work, but it would require care to make > sure that the number of operations on geodetic numbers stays small.
Ah ... a basic philosophical difference One should only ever have to-do the geodetic transforms once for any given position. Once in Local Cartesian Space stay in LCS until all calculations are done anything else is wasteful of resources, much less precise and error prone i.e. any local operations within a small area [1] should be done in the local space. i.e. origin at 0,0,0 rest derived from the Local North, Local East and Local Up vectors [1] small area == small enough so that the error introduced by local curvature is inconsequential to the geodetic transform in phi and lambda. the LCS Z will then corespond to to Geodetic Space 'Height term' Note: Areas of several kilometers in extent are certainly 'small enough' and that the work required to set up the local transform is comparable to one pass thru a 'fast' geodetic transform Cheers Norman _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
