[Proj] Re: URGENT Non-existent Projection Definition (Oblique Mercator)

[Melita Kennedy]

I'm close...I'll keep working on it. Here's the settings (notice the lonc value). Didn't we get this far before? Anyway, officially the alpha value is 337.25556. I tried it with a longer one, and the results were the same.

D:\PROJ4\proj>cs2cs +proj=latlong +datum=NAD83 +to +proj=omerc +k=0.9996 +alpha=337.25556 +lat_0=45.309166666667 +lonc=-86 +x_0=2546731.496 +y_0=-4354009.816 +no_uoff +datum=NAD83 +units=m

-86.0 43.0
499864.92       272108.92 0.000

Melita

>----------------------------------------------------------------------
>
>Date: Mon, 29 Jan 2007 01:00:12 -0500
>From: "Clever, Max" <Maxc at spicergroup.com>
>Subject: [Proj] URGENT Non-existent Projection Definition (Oblique
>	Mercator
>To: <proj at lists.maptools.org>
>
>Oscar,
> 
>Sorry for the bad coordinate comparisons.  I have read from a previous post of yours and Melita Kennedy that you were able to get the correct coordinates using the "no_off" tag using your customized proj program.  I am using proj 4.4.6 and still getting the wrong results with +no_uoff.  Does Proj446 use libproj definitions?  Here is a comparison using the example lat long that you and Melita used, and also an extra point.  Your calculations using "type = 5" and "norot, no_off" from July 23, 2006 appear to exactly match the Autodesk points  The following two points were transformed using Michigan Georef to Lat Long NAD83 in AutoDesk Map 2007.
> 
>Point 1
>-86 Longitude NAD83
>43 Latitude NAD83
>499864.5000769 X georef meters Correct
>272108.8592635 Y georef meters Correct
> 
>Point 2
>-84 Longitude NAD83
>44   Latitude NAD83
>662870.1177213 X georef meters correct
>341261.925 Y georef meters correct
> 
>Here are my results of Lat Long NAD83 to Michigan Georef using the "+no_uoff" flag on Point 1
>cs2cs +proj=latlong +datum=NAD83 +to +proj=omerc +k_0=0.9996 +alpha=337.25555555555556 +lat_0=45.30916666666667 +lonc=86 +x_0=2546731.496 +y_0=-4354009.816 +no_uoff +ellps=GRS80 +datum=NAD83 +units=m 
>-1691884.49 X, 10656222.28 Y
> 
>Here are my results of Lat Long NAD83 to Michigan Georef using the "no_rot" and "+no_uoff" flag on Point 1
>18028485.13 -2459745.46
> 
>Here are my results of Lat Long NAD83 to Michigan Georef using the neither the "no_rot" nor the "+no_uoff" flag on Point 1
>355007.17 5773612.22
>
>I know you have gotten this to work on your program, could you tell me what I am doing wrong?  Is there a different definition than "proj=omerc" in epsg format that would be the equivalent of your "type=5" omerc?  Once I get this corrected, I would hope to have this formally and permanently added to the epsg file with the proper parameters.  Thanks for the help.
>
>-Max
>
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>End of Proj Digest, Vol 32, Issue 16
>************************************