PROJCS["NAD_1983_UTM_Zone_12N", GEOGCS["GCS_North_American_1983",
DATUM["North_American_Datum_1983", SPHEROID["GRS_1980",6378137,298.257222101]], PRIMEM["Greenwich",0], UNIT["Degree",0.017453292519943295]], PROJECTION["Transverse_Mercator"], PARAMETER["latitude_of_origin",0], PARAMETER["central_meridian",-111], PARAMETER["scale_factor",0.9996], PARAMETER["false_easting",500000], PARAMETER["false_northing",0], UNIT["Meter",1]] Amanda M. Henneke IG/DB Tools - TSS Capability Center Boeing - St. Louis 314-777-6856 When One tugs at a single thing in Nature, he finds it attached to the rest of the world. -John Muir Please consider the environment before printing this e-mail. ________________________________ From: steve.tout...@inspq.qc.ca [mailto:steve.tout...@inspq.qc.ca] Sent: Wednesday, September 23, 2009 12:41 PM To: Henneke, Amanda M Cc: gdal-dev@lists.osgeo.org; gdal-dev-boun...@lists.osgeo.org Subject: RE: [gdal-dev] Translating between UTM and Geographic What is the wkt you are using for zone 12 nad83? "Henneke, Amanda M" <amanda.m.henn...@boeing.com>@lists.osgeo.org Envoyé par : gdal-dev-boun...@lists.osgeo.org 23/09/2009 01:39 PM A "gdal-dev@lists.osgeo.org" <gdal-dev@lists.osgeo.org> cc Objet RE: [gdal-dev] Translating between UTM and Geographic Here is some more information: So, here is the WKT I'm getting from my code for the "problem" source file: PROJCS["NAD_1927_UTM_Zone_11N", GEOGCS["GCS_North_American_1927", DATUM["North_American_Datum_1927", SPHEROID["Clarke_1866",6378206.4,294.9786982]], PRIMEM["Greenwich",0], UNIT["Degree",0.017453292519943295]], PROJECTION["Transverse_Mercator"], PARAMETER["latitude_of_origin",0], PARAMETER["central_meridian",-117], PARAMETER["scale_factor",0.9996], PARAMETER["false_easting",500000], PARAMETER["false_northing",0], UNIT["Meter",1]] Here's the WKT I'm creating for the destination file: GEOGCS["Geographic Coordinate System", DATUM["WGS_1984", SPHEROID["WGS_1984",6378137,298.257223563]], PRIMEM["Greenwich",0], UNIT["degree",0.0174532925199433]] Do you see any issues with that? It looks like the source file is picking up that it's NAD27... Amanda M. Henneke IG/DB Tools - TSS Capability Center When One tugs at a single thing in Nature, he finds it attached to the rest of the world. -John Muir Please consider the environment before printing this e-mail. -----Original Message----- From: gdal-dev-boun...@lists.osgeo.org [mailto:gdal-dev-boun...@lists.osgeo.org] On Behalf Of Henneke, Amanda M Sent: Wednesday, September 23, 2009 11:58 AM To: Craig Miller Cc: gdal-dev@lists.osgeo.org Subject: RE: [gdal-dev] Translating between UTM and Geographic Craig- I'm trying to have it in Geograhphic/WGS84, at least that's what I'm specifying in the code...I agree I think it is a datum error, but I don't know what to do to make it translate the datum from NAD27 to WGS84 correctly. I don't know if I can send the raster, but I can send the two shapefiles... Amanda M. Henneke IG/DB Tools - TSS Capability Center When One tugs at a single thing in Nature, he finds it attached to the rest of the world. -John Muir Please consider the environment before printing this e-mail. -----Original Message----- From: Craig Miller [mailto:craig.mil...@spatialminds.com] Sent: Wednesday, September 23, 2009 11:51 AM To: Henneke, Amanda M Subject: RE: [gdal-dev] Translating between UTM and Geographic Geographic is a projection, not a datum. What Datum is the data in the "Geographic Projection" in? E.g. you can have a map in either Geographic/NAD27 or Geographic/NAD83 (or another datum for that matter.. such as WGS84). What software are you using to display the data? If you want me to take a look, zip up the raster, and the good shapefile, and the bad shapefile and send them over. I don't have a lot of time as I'm getting ready to leave on a trip, but I'll try and squeeze it in before I leave. Craig > -----Original Message----- > From: Henneke, Amanda M [mailto:amanda.m.henn...@boeing.com] > Sent: Wednesday, September 23, 2009 9:28 AM > To: Craig Miller > Subject: RE: [gdal-dev] Translating between UTM and Geographic > > Hi Craig- > > I'm translating a shapefile (from UTM to Geographic) and then > comparing it to > > #1 A shapefile that was translated from UTM to Geographic using the software, > GlobalMapper. > #2 A raster file that was originally projected in Geographic, so that > for example I can see the points don't match up with the features they > should represent on the image. > > The shapefile that GlobalMapper translates matches up perfectly with > my raster > file. > > So my thought process is, that if Global Mapper has some way to > convert the > different projections without the shifting, how come GDAL can't do that. I'm > thinking it can, but maybe I need to give it some additional data maybe? Or > am I off? > > Thanks for your help! > > Amanda M. Henneke > IG/DB Tools - TSS Capability Center > > > When One tugs at a single thing in Nature, he finds it attached to the rest of > the world. -John Muir > Please consider the environment before printing this e-mail. > > -----Original Message----- > From: Craig Miller [mailto:craig.mil...@spatialminds.com] > Sent: Wednesday, September 23, 2009 11:21 AM > To: Henneke, Amanda M > Subject: RE: [gdal-dev] Translating between UTM and Geographic > > If you are transforming the datum from NAD27 to WGS84 then it is > expected that > your points would be shifted exactly as you describe. How are you determining > that they are shifted? > > a. Compared to a map? Is the map reprojected? Are you comparing > them to landform features or to the lat/lon grid on the map? For > example, if you have > a USGS Quad map with lat/lon lines on it based on the NAD27 datum then those > lat/lon lines ONLY show the lat/lon using that datum. If you plot > points that > have been shifted to the new datum, they will not agree with those > NAD27 lines > since the new points are based on lat/lon NAD83. > > b. Comparing lat/lon directly? The points have been transformed. Lat/lon > are relative to a datum and lan/lon NAD27 coords and lat/lon NAD83 > coords will > have different values. > > Craig > > > > -----Original Message----- > > From: gdal-dev-boun...@lists.osgeo.org [mailto:gdal-dev- > > boun...@lists.osgeo.org] On Behalf Of Henneke, Amanda M > > Sent: Wednesday, September 23, 2009 8:17 AM > > To: gdal-dev@lists.osgeo.org > > Subject: [gdal-dev] Translating between UTM and Geographic > > > > Hello all- > > > > I'm trying to figure out how to reproject some points from a UTM > projection to > > Geographic (WGS84) projection. This works fine when I'm working in > > UTM > Zone > > 12 with NAD83. When I try the same code for Zone 11 NAD27, I get a > > slight shift in the points (to the east) and an extremely slight > > shift up (to the north). > > > > I've included the following code as it stands now, I've tried all > > sorts of things thinking that I need to somehow include more > > information for the > new > > spatial reference (the destination SR), and so far I'm coming up empty... > > > > Anyone have any ideas what I'm missing? > > > > Where sSpRefParams is a string that contains the WKT projection > information > > from a valid layer... > > > > srOld = new OSGeo.OSR.SpatialReference(sSpRefParams); > > > > srNew.SetGeogCS("Geographic Coordinate System", > OSGeo.OSR.Osr.SRS_DN_WGS84, > > OSGeo.OSR.Osr.SRS_DN_WGS84, OSGeo.OSR.Osr.SRS_WGS84_SEMIMAJOR, > > OSGeo.OSR.Osr.SRS_WGS84_INVFLATTENING, "Greenwich", 0.0, "degree", > > 0.0174532925199433); > > > > ctTransform = new OSGeo.OSR.CoordinateTransformation(srOld, srNew); > > > > > > > > Amanda M. Henneke > > IG/DB Tools - TSS Capability Center > > > > > > > When One tugs at a single thing in Nature, he finds it attached to > > the > rest of > > the world. -John Muir > > Please consider the environment before printing this e-mail. > > > > > > _______________________________________________ > > gdal-dev mailing list > > gdal-dev@lists.osgeo.org > > http://lists.osgeo.org/mailman/listinfo/gdal-dev _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
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