[Proj] URGENT Non-existent Projection Definition (Oblique Mercator RSO Natural Origin)

Oscar van Vlijmen ovv at hetnet.nl
Sat Jan 27 14:16:42 EST 2007

> From: "Clever, Max"
> Date: Fri, 26 Jan 2007 19:59:58 -0500
> Subject: [Proj] URGENT Non-existent Projection Definition (Oblique Mercator
RSO Natural Origin)

> I am emailing to push for the addition of the coordinate system known as the
> Rectified Skew Orthomorphic Oblique Mercator Natural Origin (sometimes known
> as Hotine Oblique Mercator Natural Origin).  I have come to the conclusion
> that this projection is not capable of being defined properly in the current
> version of Proj. 
> If you read through prior posts, you will see that a proper solution has never
> been developed .....
> Below is an outline of the correct transformation of an example coordinate and
> also the incorrect transformation results from using proj.

The examples you provided seemed to me overly complex and not complete.
(a) What has reprojecting through LCC got to do with Oblique Mercator
(b) If you merely provide easting, northing without telling from which
latitude, longitude they were calculated, nothing can be properly diagnosed
or checked.

Furthermore: several times it was mentioned on this list that Michigan,
Alaska and Borneo RSO's can be done with libproj's and proj's omerc with the
no_off/no_uoff flag set and in some cases with an adjusted false

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