[OSRS-PROJ] Horrors of --- Krovak projection

Gerald I. Evenden gerald.evenden at verizon.net
Fri Feb 14 22:19:55 EST 2003


Indeed, this IS the horrors of Krovak.

I went back to fundamentals as the statement of the definition
of the Krovak projections seems strait forward (though a bit
weird).

1. convert latitude to Gaussian sphere.  Use Snyder Working
	Manual p. 15 or SP251 p. 86(eqn 256) (both same)

2. translate lat/lon on sphere --- see Snyder or proj doc.

3. project translated coords onto tangential cone with Lambert CC.

All the needed math seems to be available and, except for the
fuzzy logic defining the parameters, should be straight forward.

HOWEVER, in all math descriptions and code versions I have obtained
bear little resemblance to the above steps.  To be sure, reorganizing
and manipulations may change the appearance but I cannot account
for all the machinations I see.  With one exception, the axis
translations do make sense.

I must be missing something.

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