Hi, sorry it took me so long to notice this:
The "polar steregraphic projection" as documented is confusing.
1. I think it should be called "stereographic", since "polar
stereographic" is often used to mean a stereographic projection whose
tangent point is the north or south pole.
2. the meaning of the map parameters are unclear. I realize that you are
following FGDC, but FGDC is pretty frustrating since there is no text
explaining in more detail what they mean (actually they reference
Snyders earlier book, but it doesnt have those names).
The following set would be consistent with the reference PROJ4 docs at
http://www.remotesensing.org/geotiff/proj_list/polar_stereographic.html,
and the reference text by Snyder (Map Projections - A working manual)
(actually both Snyder books):
Latitude of natural origin / tangent point
Longitude of natural origin / tangent point
Scale factor at natural origin / tangent point
False Easting
False Northing
In any case, these names are consistent with FGDC "Stereographic"
projection:
Stereographic =
Longitude_of_Projection_Center +
Latitude_of_Projection_Center +
False_Easting +
False_Northing
except they forgot the scale factor.
since the polar stereographic is the special case of stereographic with
lat origin = 90, i think you should just use the stereographic.
So I would reccomend changing the name to "Stereographic", and using the
FGDC "Stereographic" projection names with the addition of
Scale_Factor_at_Natural_Origin
Received on Tue Oct 14 2003 - 11:34:43 BST
