[gdal-dev] Help with Maine state plane US feet

Smith, Michael Michael.Smith at maine.gov
Mon Jan 26 09:01:29 EST 2009


I am trying to work with several aerial photos which are in Maine State
Plane West, NAD83, US feet.  This is a commonly-used projection in Maine
(along with Maine East), yet it is not found in the pcs.csv file that
comes with FWTools/GDAL.  In fact although there are several iterations
of state plane for Maine in that file, none are in feet.

I have hacked around a bit without success.  The two EPSG codes I am
trying to add are 26847 http://spatialreference.org/ref/epsg/26847/  and
26848 http://spatialreference.org/ref/epsg/26848/.  I added the values
below to the table based on what I saw as examples in other entries:
COORD_REF_SYS_CODE	COORD_REF_SYS_NAME	UOM_CODE
SOURCE_GEOGCRS_CODE	COORD_OP_CODE	COORD_OP_METHOD_CODE	SHOW_CRS
DEPRECATED	PARAMETER_CODE_1	PARAMETER_VALUE_1
PARAMETER_UOM_1	PARAMETER_CODE_2	PARAMETER_VALUE_2
PARAMETER_UOM_2	PARAMETER_CODE_3	PARAMETER_VALUE_3
PARAMETER_UOM_3	PARAMETER_CODE_4	PARAMETER_VALUE_4
PARAMETER_UOM_4	PARAMETER_CODE_5	PARAMETER_VALUE_5
PARAMETER_UOM_5	

26847	NAD83 / Maine East (ftUS)	9003	4269	11831	9807
1	0	8801	43.4	9110	8802	-68.3	9110	8805
0.9999	9201	8806	300000	9001	8807	0	9001	
26848	NAD83 / Maine West (ftUS)	9003	4269	11832	9807
1	0	8801	42.5	9110	8802	-70.1	9110	8805
0.999967	9201	8806	900000	9001	8807	0	9001	

Yet when I use those EPSG codes the imagery does not align correctly
(way way off) in GIS software including ArcGIS.

I tried two other methods, one using the PROJ4 description and secondly
using the ESRI projection file for
NAD_1983_StatePlane_Maine_West_FIPS_1802_Feet.  In all cases the imagery
is way way way out of Maine.  Examining the image in ArcGIS shows it is
Transverse Mercator and has the same parameters as State Plane feet, but
it's screwed up.

Yet if I'm in ArcGIS and I assign the projection file to the image
manually, it works fine.  I intend to put the imagery in MapServer WMS,
so I need to get this worked out in GDAL first.

Any suggestions?

**********
Michael Smith
State GIS Manager
Maine Office of GIS 

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