[Proj] Transverse Mercator algorithm
Gerald I. Evenden
geraldi.evenden at gmail.com
Fri Sep 5 12:56:35 EDT 2008
A couple of notes:
1. Of the etmerc, ktmerc and ftmerc extended range versions of TM, etmerc
appears to be the winner in precision as one approaches 90,0. When I figure
out how to get maxima to generate a grid of numbers I will try to make a
contour plot of precision comparisons. Thus the combination of highest speed
and best precision goes to Denmark.
2. I tried out tmerc along the CM which tests my version of M(phi) or meridian
distance procedure that I revised a couple of years ago against the maxima
procedure. Scripts and results follow:
(%i12) xya:tm1(90b0,0b0)$ float(xya);
(%o13) [0.0, 9997964.943020998, - 6.837286269353478E-119, 0.9996]
gie at charon:~$ lproj +proj=tmerc +ellps=WGS84 +k_0=0.9996 -f %.9f
0 90
0.000000000 9997964.943020998
--
The whole religious complexion of the modern world is due
to the absence from Jerusalem of a lunatic asylum.
-- Havelock Ellis (1859-1939) British psychologist
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