Qualcuno cercava di aprire gli mdb di recente se non ricordo male ...
----- Forwarded message from Even Rouault <even.rouault@mines-paris.org> -----
Date: Sat, 22 Jan 2011 16:42:49 +0100
From: Even Rouault <even.rouault@mines-paris.org>
Subject: Re: [gdal-dev] Geomedia mdb files
To: gdal-dev@lists.osgeo.org
Cc: Christian Andersen <christianhelring@gmail.com>,
"Moskovitz,
Bob" <Bob.Moskovitz@conservation.ca.gov>
In-Reply-To: <4CB48DF7.2080302@pobox.com>
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List-Id: "Discussion for developers using and building GDAL/OGR."
<gdal-dev.lists.osgeo.org>
Hi,
I've just added a read-only geomedia driver in GDAL trunk (GDAL 1.9.0dev).
Testing is appreciated.
It would be usefull if someone could provide a small and freely redistribuable
geomedia .mdb (possibly hand-made with fake data) with different types of
geometries (1 feature for each geometry type is enough) so that it can be
included in the autotest suite. For now, it has just been tested with the
MMSDTestDB.zip attachment found on http://forum.manifold.net/forum/t106539.11
What is mainly missing is SRS support. I see that the GCoordSystem contains
all the info. For the above example :
Stor2CompMatrix1 (Real) = 0.3048
GeodeticDatum (Integer) = 0
Ellipsoid (Integer) = 21
EquatorialRadius (Real) = 6378407.621
InverseFlattening (Real) = 298.269875040474
ProjAlgorithm (Integer) = 2
AzimuthAngle (Real) = (null)
FalseX (Real) = 247193.2944
FalseY (Real) = 0
Hemisphere (Integer) = (null)
LatOfOrigin (Real) = 41.75
LatOfTrueScale (Real) = (null)
LonOfOrigin (Real) = -89.4222222222222
RadOfStandCircle (Real) = (null)
ScaleReductFact (Real) = 1
StandPar1 (Real) = 42.9083333333333
StandPar2 (Real) = 43.2305555555556
But the GeodeticDatum, Ellipsoid and ProjAlgorithm fields presumably map to
enumerations, so examples of databases using various SRS (starting with the
most common ones like lat/long WGS84 and UTM WGS84) with the "text"
description of the SRS would be necessary to establish this mapping. Unless
someone knows where to find a spec of this ?
From the above sample and a bit of googling, I've deduced this is equivalent
to the following ESRI WKT :
PROJCS["NAD_1983_HARN_Adj_WI_Dane_Feet",GEOGCS["GCS_NAD_1983_HARN_Adj_WI_Dane",DATUM["D_NAD_1983_HARN_Adj_WI_DN",SPHEROID["GRS_1980_Adj_WI_DN",6378407.621,298.269876997368]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Lambert_Conformal_Conic"],PARAMETER["False_Easting",811000.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",-89.42222222222223],PARAMETER["Standard_Parallel_1",42.90833333333333],PARAMETER["Standard_Parallel_2",43.23055555555555],PARAMETER["Latitude_Of_Origin",41.75],UNIT["Foot_US",0.3048006096012192]]
So ProjAlgorithm 2 is likely meaning Lambert_Conformal_Conic_2SP and Ellipsoid
= 21 = GRS_1980_Adj_WI_DN ?
Best regards,
Even
Le mardi 12 octobre 2010 18:33:59, Frank Warmerdam a écrit :
Moskovitz, Bob wrote:
> Frank,
>
> I'm also interested in seeing a Geomedia driver for gdal. Btw, gvSIG has
> a Geomedia plugin (see https://code.google.com/p/extmdb ). This might
> help you figure out how to make a driver for gdal.Bob,
Interesting. Using the extmdb MDBGeometryAdapter.java code it should be
possible to fairly easily implement geomedia feature reading in OGR.Anyone interested in taking the task on or funding it?
Best regards,
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