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

Clever, Max Maxc at spicergroup.com
Sun Jan 28 22:00:12 PST 2007


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
-------------- next part --------------
A non-text attachment was scrubbed...
Name: winmail.dat
Type: application/ms-tnef
Size: 5184 bytes
Desc: not available
URL: <http://lists.osgeo.org/pipermail/proj/attachments/20070129/549d075c/attachment.bin>


More information about the Proj mailing list