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WGS84 problem
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Hello, I have problem with dataset (MySQL) which is stored in integer WGS84 coords, so it is multiplied by 1 million. For example coordinate 24.002525 is stored as 24002525 (same rule for both coords). Is there any magic in uDig to display this?
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You can define your own custom "CRS" for the layer.
1. right click on the layer (after you have loaded it) 2. choose the CRS property page 3. select a good normal WGS84 starting point (such as "EPSG:4326") it should look something like this: GEOGCS["WGS 84", DATUM["World Geodetic System 1984", SPHEROID["WGS 84", 6378137.0, 298.257223563, AUTHORITY["EPSG","7030"]], AUTHORITY["EPSG","6326"]], PRIMEM["Greenwich", 0.0, AUTHORITY["EPSG","8901"]], UNIT["degree", 0.017453292519943295], AXIS["Geodetic longitude", EAST], AXIS["Geodetic latitude", NORTH], AUTHORITY["EPSG","4326"]] 4. Switch to the tab that lets you define your own 5. Modify the "well known text" description so that the axis information is different (and matches your data) I hunted down some examples for you here: - http://docs.geoserver.org/latest/en/user/advanced/crshandling/customcrs.html it looks like the "scale factor" may actually just allow you to do what you want? The "Well known text" is actually a standard defined by the OGC - so if you really get stuck you can read the standard? --
Jody Garnett On Wednesday, 7 September 2011 at 5:38 PM, Mirza Hadzic wrote:
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While scaling a projected system might be useful, I don't think that
it makes much (physical) sense to scale a geographic coordinate system. So I assume there is no way to scale the WGS84 system (but I might be wrong) from the projection definition. Perhaps through the new sld functions that geotools added lately? But I would not know how. Jody? Ciao, Andrea On Wed, Sep 7, 2011 at 2:13 PM, Jody Garnett <[hidden email]> wrote: > You can define your own custom "CRS" for the layer. > 1. right click on the layer (after you have loaded it) > 2. choose the CRS property page > 3. select a good normal WGS84 starting point (such as "EPSG:4326") it should > look something like this: > GEOGCS["WGS 84", > DATUM["World Geodetic System 1984", > SPHEROID["WGS 84", 6378137.0, 298.257223563, AUTHORITY["EPSG","7030"]], > AUTHORITY["EPSG","6326"]], > PRIMEM["Greenwich", 0.0, AUTHORITY["EPSG","8901"]], > UNIT["degree", 0.017453292519943295], > AXIS["Geodetic longitude", EAST], > AXIS["Geodetic latitude", NORTH], > AUTHORITY["EPSG","4326"]] > 4. Switch to the tab that lets you define your own > 5. Modify the "well known text" description so that the axis information is > different (and matches your data) > I hunted down some examples for you here: > - http://docs.geoserver.org/latest/en/user/advanced/crshandling/customcrs.html > it looks like the "scale factor" may actually just allow you to do what you > want? The "Well known text" is actually a standard defined by the OGC - so > if you really get stuck you can read the standard? > -- > Jody Garnett > > On Wednesday, 7 September 2011 at 5:38 PM, Mirza Hadzic wrote: > > Hello, I have problem with dataset (MySQL) which is stored in integer WGS84 > coords, so it is multiplied by 1 million. For example coordinate 24.002525 > is stored as 24002525 (same rule for both coords). Is there any magic in > uDig to display this? > _______________________________________________ > udig-users mailing list > [hidden email] > http://lists.refractions.net/mailman/listinfo/udig-users > > > _______________________________________________ > udig-users mailing list > [hidden email] > http://lists.refractions.net/mailman/listinfo/udig-users > > udig-users mailing list [hidden email] http://lists.refractions.net/mailman/listinfo/udig-users |
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The correct solution here is to define a custom CRS that actually matches the data; the uDig environment has the tools to do this; what is needed is a bit of research / reading.
I do not think there is a need to look functions; the data is *correct* - we just need to have the proper description so that uDig can use it. Did you want to mess with the unit setting a bit? I do not have any sample data so I feel a bit like I am making suggestions from the side line. There is some scary background reading here: http://docs.geotools.org/latest/userguide/library/referencing/internal.html But really all the same settings are available from WKT; it would be easier to read the standard or ask the person who gave you the data for the correct WTK (or ".prj" file). --
Jody Garnett On Thursday, 8 September 2011 at 9:39 PM, andrea antonello wrote:
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Still I am not convinced Jody. In my understanding a geographic
reference system lives in the ellipsoid space. Therefore it doesn't make sense to build it with coordinates that get outside +-180, +-90. If we are talking about projected systems, ok, you do whatever you want, but not in the geographic space. So, I guess there is no way to handle that in the prj file. Jody, isn't there a way to use some style geometry function to apply a transform to the geometry? Andrea On Thu, Sep 8, 2011 at 11:24 PM, Jody Garnett <[hidden email]> wrote: > The correct solution here is to define a custom CRS that actually matches > the data; the uDig environment has the tools to do this; what is needed is a > bit of research / reading. > I do not think there is a need to look functions; the data is *correct* - we > just need to have the proper description so that uDig can use it. > Did you want to mess with the unit setting a bit? I do not have any sample > data so I feel a bit like I am making suggestions from the side line. > There is some scary background reading > here: http://docs.geotools.org/latest/userguide/library/referencing/internal.html > But really all the same settings are available from WKT; it would be easier > to read the standard or ask the person who gave you the data for the correct > WTK (or ".prj" file). > -- > Jody Garnett > > On Thursday, 8 September 2011 at 9:39 PM, andrea antonello wrote: > > While scaling a projected system might be useful, I don't think that > it makes much (physical) sense to scale a geographic coordinate > system. > So I assume there is no way to scale the WGS84 system (but I might be > wrong) from the projection definition. > > Perhaps through the new sld functions that geotools added lately? But > I would not know how. Jody? > > Ciao, > Andrea > > > > On Wed, Sep 7, 2011 at 2:13 PM, Jody Garnett <[hidden email]> wrote: > > You can define your own custom "CRS" for the layer. > 1. right click on the layer (after you have loaded it) > 2. choose the CRS property page > 3. select a good normal WGS84 starting point (such as "EPSG:4326") it should > look something like this: > GEOGCS["WGS 84", > DATUM["World Geodetic System 1984", > SPHEROID["WGS 84", 6378137.0, 298.257223563, AUTHORITY["EPSG","7030"]], > AUTHORITY["EPSG","6326"]], > PRIMEM["Greenwich", 0.0, AUTHORITY["EPSG","8901"]], > UNIT["degree", 0.017453292519943295], > AXIS["Geodetic longitude", EAST], > AXIS["Geodetic latitude", NORTH], > AUTHORITY["EPSG","4326"]] > 4. Switch to the tab that lets you define your own > 5. Modify the "well known text" description so that the axis information is > different (and matches your data) > I hunted down some examples for you here: > - http://docs.geoserver.org/latest/en/user/advanced/crshandling/customcrs.html > it looks like the "scale factor" may actually just allow you to do what you > want? The "Well known text" is actually a standard defined by the OGC - so > if you really get stuck you can read the standard? > -- > Jody Garnett > > On Wednesday, 7 September 2011 at 5:38 PM, Mirza Hadzic wrote: > > Hello, I have problem with dataset (MySQL) which is stored in integer WGS84 > coords, so it is multiplied by 1 million. For example coordinate 24.002525 > is stored as 24002525 (same rule for both coords). Is there any magic in > uDig to display this? > _______________________________________________ > udig-users mailing list > [hidden email] > http://lists.refractions.net/mailman/listinfo/udig-users > > > _______________________________________________ > udig-users mailing list > [hidden email] > http://lists.refractions.net/mailman/listinfo/udig-users > > udig-users mailing list [hidden email] http://lists.refractions.net/mailman/listinfo/udig-users |
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Hi Andrea:
It sounded like the data was multiplied by 1,000,000 - in this case I would expect the coordinate range to be +/-180,000,000 and +- 90,000,000 in order to correctly describe this. I have run into this once before where information for a region was measured in cm (so the data could be recorded in integers rather than floating point numbers). Once we had correctly described this in the CRS - and after that everything rendered fine. You can use a function as part of each and every symbolizer in order to manipulate the geometry; this would allow you to preprocess the data if you desired (in this case dividing by 1,000,000). Jody On 09/09/2011, at 5:13 PM, andrea antonello wrote: > Still I am not convinced Jody. In my understanding a geographic > reference system lives in the ellipsoid space. Therefore it doesn't > make sense to build it with coordinates that get outside +-180, +-90. > If we are talking about projected systems, ok, you do whatever you > want, but not in the geographic space. > So, I guess there is no way to handle that in the prj file. > > Jody, isn't there a way to use some style geometry function to apply a > transform to the geometry? > > Andrea > > > On Thu, Sep 8, 2011 at 11:24 PM, Jody Garnett <[hidden email]> wrote: >> The correct solution here is to define a custom CRS that actually matches >> the data; the uDig environment has the tools to do this; what is needed is a >> bit of research / reading. >> I do not think there is a need to look functions; the data is *correct* - we >> just need to have the proper description so that uDig can use it. >> Did you want to mess with the unit setting a bit? I do not have any sample >> data so I feel a bit like I am making suggestions from the side line. >> There is some scary background reading >> here: http://docs.geotools.org/latest/userguide/library/referencing/internal.html >> But really all the same settings are available from WKT; it would be easier >> to read the standard or ask the person who gave you the data for the correct >> WTK (or ".prj" file). >> -- >> Jody Garnett >> >> On Thursday, 8 September 2011 at 9:39 PM, andrea antonello wrote: >> >> While scaling a projected system might be useful, I don't think that >> it makes much (physical) sense to scale a geographic coordinate >> system. >> So I assume there is no way to scale the WGS84 system (but I might be >> wrong) from the projection definition. >> >> Perhaps through the new sld functions that geotools added lately? But >> I would not know how. Jody? >> >> Ciao, >> Andrea >> >> >> >> On Wed, Sep 7, 2011 at 2:13 PM, Jody Garnett <[hidden email]> wrote: >> >> You can define your own custom "CRS" for the layer. >> 1. right click on the layer (after you have loaded it) >> 2. choose the CRS property page >> 3. select a good normal WGS84 starting point (such as "EPSG:4326") it should >> look something like this: >> GEOGCS["WGS 84", >> DATUM["World Geodetic System 1984", >> SPHEROID["WGS 84", 6378137.0, 298.257223563, AUTHORITY["EPSG","7030"]], >> AUTHORITY["EPSG","6326"]], >> PRIMEM["Greenwich", 0.0, AUTHORITY["EPSG","8901"]], >> UNIT["degree", 0.017453292519943295], >> AXIS["Geodetic longitude", EAST], >> AXIS["Geodetic latitude", NORTH], >> AUTHORITY["EPSG","4326"]] >> 4. Switch to the tab that lets you define your own >> 5. Modify the "well known text" description so that the axis information is >> different (and matches your data) >> I hunted down some examples for you here: >> - http://docs.geoserver.org/latest/en/user/advanced/crshandling/customcrs.html >> it looks like the "scale factor" may actually just allow you to do what you >> want? The "Well known text" is actually a standard defined by the OGC - so >> if you really get stuck you can read the standard? >> -- >> Jody Garnett >> >> On Wednesday, 7 September 2011 at 5:38 PM, Mirza Hadzic wrote: >> >> Hello, I have problem with dataset (MySQL) which is stored in integer WGS84 >> coords, so it is multiplied by 1 million. For example coordinate 24.002525 >> is stored as 24002525 (same rule for both coords). Is there any magic in >> uDig to display this? >> _______________________________________________ >> udig-users mailing list >> [hidden email] >> http://lists.refractions.net/mailman/listinfo/udig-users >> >> >> _______________________________________________ >> udig-users mailing list >> [hidden email] >> http://lists.refractions.net/mailman/listinfo/udig-users >> >> > _______________________________________________ > udig-users mailing list > [hidden email] > http://lists.refractions.net/mailman/listinfo/udig-users _______________________________________________ udig-users mailing list [hidden email] http://lists.refractions.net/mailman/listinfo/udig-users |
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