[gdal-dev] Michigan GeoRef - Michigan Oblique Mercator - EPSG:3078

[Stephen Woodbridge]

I'm not sure how this works in gdal/ogr, but proj library uses the tag 
before the ":" as the name of a file containing the projection data. 
gdal/ogr may use an different database of projection information.

Anyway, the following show these projection definitions:

$ grep "Michigan GeoRef" /usr/share/proj/esri

# NAD 1927 Michigan GeoRef Feet US
<102120> +proj=omerc +lat_0=45.30916666666666 +lonc=-86 
+alpha=337.255555555556 +k=0.9996 +x_0=2546731.495961392 
+y_0=-4354009.816002033 +ellps=clrk66 +datum=NAD27 
+to_meter=0.3048006096012192  no_defs <>
# NAD 1983 Michigan GeoRef Feet US
<102121> +proj=omerc +lat_0=45.30916666666666 +lonc=-86 
+alpha=337.255555555556 +k=0.9996 +x_0=2546731.495961392 
+y_0=-4354009.816002033 +ellps=GRS80 +datum=NAD83 
+to_meter=0.3048006096012192  no_defs <>
# NAD 1927 Michigan GeoRef Meters
<102122> +proj=omerc +lat_0=45.30916666666666 +lonc=-86 
+alpha=337.255555555556 +k=0.9996 +x_0=2546731.496 +y_0=-4354009.816 
+ellps=clrk66 +datum=NAD27 +units=m  no_defs <>
# NAD 1983 Michigan GeoRef Meters
<102123> +proj=omerc +lat_0=45.30916666666666 +lonc=-86 
+alpha=337.255555555556 +k=0.9996 +x_0=2546731.496 +y_0=-4354009.816 
+ellps=GRS80 +datum=NAD83 +units=m  no_defs <>


So you might be able to reference one of these projections via

ESRI:102123 for example for the last projection listed above. Or you 
might be able to copy one or all of these projection definitions to the 
/usr/shar/proj/epsg file and rename the number to an appropriate EPSG 
definition, then try referencing if from gdal/ogr

-Steve

On 6/26/2011 11:06 AM, Howard Y wrote:
> All,
>
> I was wondering if there has been any progress in addressing the various
> problems associated with correctly projecting to and from Michigan Oblique
> Mercator (EPSG:3078 and its brethren), as brought up in tickets 2475, 3038,
> and 3311, among others.
>
> As you may know, the State of Michigan, USA, distributes GIS vector and
> raster files in the Michigan Oblique Mercator ("Michigan GeoRef")
> projection.  Commercial software packages from ESRI and others seem to be
> able to handle data projected in this format, but open source software
> packages that depend on GDAL/OGR routines do not seem to be able, for the
> most part, to do so.  I've found QGIS and MapWindow to be among the software
> packages that cannot successfully handle Michigan GeoRef using existing
> definitions for EPSG:3078 and its kin.  (The only exception seems to be
> uDig.  For some reason, uDig appears to be able to bring in a Michigan
> GeoRef shapefile and successfully reproject it to Michigan State Plane
> Coordinates, for example.)
>
> I feel that this problem may be the single biggest factor that stands in the
> way of wider adoption of open source GIS software in Michigan.  I realize
> that you are all busy dealing with a ton of other issues and tickets, and I
> am grateful for all that you've done for us out here.  But if the Michigan
> GeoRef issue were successfully addressed, it would really provide a great
> boost to open source software their enthusiasts in our state!
>
> Thank you for your time, and keep up the good work!
>
> Howard Yamaguchi
>
> --
> View this message in context: http://osgeo-org.1803224.n2.nabble.com/Michigan-GeoRef-Michigan-Oblique-Mercator-EPSG-3078-tp6517423p6517423.html
> Sent from the GDAL - Dev mailing list archive at Nabble.com.
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