[OSRS-PROJ] Roussilhe Stereographic Projection

[Gerald Evenden]

A few additional notes on the stereographics:

1.  +proj=sterea and +proj=rouss compare quite closely and the former
    could be used by those with current libraries to handle Polish grids 
if
    their accuracy needs are not in the cm. range.

2.  +proj=stere (of GCTP fame) produces larger differences and also has
    slightly larger scale errors.  If one is not replicating existing 
grid systems
    using +proj=stere or UPS, I would recommend +proj=sterea for oblique/
    equitorial applications.

3.  While doing the documentation for the stereographic it was readily 
apparent
     that, softwarewise, sterea should be part of the PJ_stere.c file.  
Thus the next
     release will be missing PJ_sterea.c.  Lest anyone panic, the 
+proj=sterea
     entry will still be there and all operations will match previous 
libraries.  If
     polar aspect is chosen in sterea it will resort to the same 
algorithm used
     in stere (which does not go through conformal sphere).
_____________________________________
Jerry and the low riders: Daisy Mae and Joshua

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