[Proj] OT: Geotrans's Neys Projection - Modified Lambert Conformal Conic

[proj-admin at remotesensing.org]

The GeoTrans documentation says:

"A.1.25 NEY?S (MODIFIED LAMBERT CONFORMAL CONIC) PROJECTION
The Ney's (Modified Lambert Conformal Conic) projection is a conformal
projection in which the projected parallels are expanded slightly to form
complete concentric circles centered at the pole. As shown in Figure A-27,
the projected meridians are radii of concentric circles that meet at the
pole. Ney's is a limiting form of the Lambert Conformal Conic. There are
two parallels, called standard parallels, along which the point scale
factor is one. One parallel is at either ¡Ó71 or ¡Ó74 degrees. The other
parallel is at ¡Ó89 59 59.0 degrees, depending on which hemisphere the first
parallel is in.
Ney's (Modified Lambert Conformal Conic) is used near the poles. Scale
distortion is small 25¢X to 30¢X from the pole. Distortion rapidly increases
beyond this.
The Easting\X and Northing\Y coordinates range from -40,000,000 to
40,000,000.


"?    1st Standard Parallel ? A latitude value that specifies one of the
two the parallels where the point scale factor is 1.0.  The 1st Standard
Parallel is either „b71 or „b74 degrees. The hemisphere of the Origin
Latitude determines the sign.

?     2nd Standard Parallel ? A latitude value that specifies one of the
two the parallels where the point scale factor is 1.0.  The 2nd Standard
Parallel is fixed at „b89 59 59.0 degrees. The hemisphere of the Origin
Latitude determines the sign."

Other than these specifics regarding the choice for the Standard Parallels,
the Ney's Projection is a standard Lambert Conformal Conic in a secant
(POLAR) case.

Note that: "Ney?s (Modified Lambert Conformal Conic) projection coordinates
consist of two fields labeled Easting/X and Northing/Y.  The legal values
for the Easting/X and the Northing/Y fields are optionally signed real
values, with up to three decimal places, in meters.  The coordinates must
designate a point that is located within the boundaries of the specified
Ney?s (Modified Lambert Conformal Conic) projection."

Ney's Projection is a POLAR (aspect) Projection.

GeoTrans does have its warts, but this explanation is crystal-clear to a
practitioner in the field.

Cliff Mugnier
LOUISIANA STATE UNIVERSITY

-----------------------------------

I cannot find any reference to "Neys" projection in my references or
bibiography
listings.

Snyder mentions some alternative Lambert Conics; one based upon "Gauss
projection."  Perhaps using the conformal projection to the sphere?
But Neys
never appears in any index.  Perhaps Russian, but the name does not
sound
like a Russian name.

The NIMA GeoTrans stuff is completely incomprehensible so I was not able
to verify the location of any related material in the remotesensing
distribution.

If anyone can supply a reference I would be glad to look into it.

On Apr 18, 2004, at 9:24 PM, proj-admin at remotesensing.org wrote:

> Hello All,
> Anyone familiar with the Neys projection found in the GeoTrans package?
>
> It is stated as being a "Modified Lambert Conformal Conic", but I
> could not
> find any further information in my reference books or online.
> Or is there a more known name for this? Is this supported by proj4?
>
> Just any information on this will do.
>
> Best regards,
> Paul.
_____________________________________
Jerry and the low riders: Daisy Mae and Joshua

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