[Proj] trouble using Michigan GeoRef projection

[Dylan Keon]

Hello,

I posted this question to mapserver-users and Frank W. replied, 
suggesting that I try this mailing list.  My original question and 
Frank's reply are copied below.  Thanks for any assistance.

--Dylan



>> Hi,
>> 
>> I'm trying to use a layer that's projected in the "Michigan GeoRef"
>> projection, but I can't get it to line up with other data.  I'm using
>> the projection parameters provided by the state of Michigan
>> (http://www.michigan.gov/documents/DNR_Map_Proj_and_MI_Georef_Info_20889_7.pdf).
>> 
>> Here's what I get when trying to line up a Michigan layer (GeoRef
>> projection) with a national 24k quad index (geographic), putting
>> everything into geographic for now:
>> 
>>    http://gis.nacse.org/mstemp/109267161738211.png
>> 
>> I haven't found examples of this online, and wonder if I messed up a
>> PROJ definition or something.  Thanks for any help.  Mapfile is below.
>> 
>> --Dylan
>> 
>> 
>> NAME 'test'
>> SIZE 640 480
>> STATUS ON
>> EXTENT -126 34 -66 46
>> UNITS DD
>> 
>> IMAGETYPE png
>> 
>> WEB
>>   IMAGEPATH '/www/temp/'
>>   IMAGEURL '/temp/'
>> END
>> 
>> PROJECTION
>>   'init=epsg:4326' #latlon
>> END
>> 
>> LAYER
>>   NAME 'quad_index'
>>   DATA '/gis/data/us/24kgrid.shp'
>>   STATUS DEFAULT
>>   TYPE POLYGON
>>   CLASS
>>     COLOR -1 -1 -1
>>     OUTLINECOLOR 0 0 255
>>   END
>>  PROJECTION
>>     'init=epsg:4326' #latlon
>>   END
>> END
>> 
>> LAYER
>>   NAME 'ecoregions'
>>   DATA '/gis/data/mi/ecoreg100'
>>   STATUS DEFAULT
>>   TYPE POLYGON
>>   CLASS #simple for now
>>     COLOR 198 123 48
>>   END
>>   PROJECTION #NAD 1983 Michigan GeoRef Meters <102123>
>>     'proj=omerc'
>>     'k_0=0.9996'
>>     'lat_0=45.30916666666666'
>>     'alpha=337.255555555556'
>>     'lonc=-86'
>>     #'x_0=2546731.496'    # PROJ
>>     #'y_0=-4354009.816'   # manual
>>     #'ellps=GRS80'        # says these are not
>>     #'datum=NAD83'        # needed for oblique mercator,
>>     #'units=m'            # but I tried them too,
>>     #'no_defs'            # in various combinations
>>   END
>> END
>> 
>> END
>>



> Dylan,
> 
> Hmm, I made an effort but couldn't get this to work.  I would suggest you
> take your question to the PROJ.4 mailing list.  I would also include that
> ESRI defines this projection as:
> 
> PROJCS["NAD_1983_Michigan_GeoRef_Meters",
>     GEOGCS["GCS_North_American_1983",
>         DATUM["D_North_American_1983",
>             SPHEROID["GRS_1980",6378137,298.257222101]],
>         PRIMEM["Greenwich",0],
>         UNIT["Degree",0.017453292519943295]],
>     PROJECTION["Hotine_Oblique_Mercator_Azimuth_Natural_Origin"],
>     PARAMETER["False_Easting",2546731.496],
>     PARAMETER["False_Northing",-4354009.816],
>     PARAMETER["Scale_Factor",0.9996],
>     PARAMETER["Azimuth",337.255555555556],
>     PARAMETER["Longitude_Of_Center",-86],
>     PARAMETER["Latitude_Of_Center",45.30916666666666],
>     UNIT["Meter",1]]
> 
> And stress lat/long value provided for the GeoRef projection origin in the
> .pdf file referenced.  While a test point at the origin is the worst kind of
> test point for a projection, it is something to work with.  I couldn't even
> get it to work out properly.
> 
> Hopefully Gerald Evenden will know whats up.
> 
> Best regards,
> -- 
> ---------------------------------------+--------------------------------------
> I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
> light and sound - activate the windows | http://pobox.com/~warmerdam
> and watch the world go round - Rush    | Geospatial Programmer for Rent