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

[proj-admin at remotesensing.org]

Please Sir,
Where do I find this documentation? It does not seems to be in
the library I downloaded.

Best regards,
Paul.

----- Original Message ----- 
From: <proj-admin at remotesensing.org>
To: <proj at remotesensing.org>
Sent: Tuesday, April 20, 2004 3:07 AM
Subject: Re: [Proj] OT: Geotrans's Neys Projection - Modified Lambert
Conformal Conic


>
>
>
>
> 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.
> _____________________________________
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>
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